High Mercury Guide: Standard & Expert

"Waters, heed my command!"



High Mercury's Trial is a challenge quest centered on a boss battle with High Mercury, unlocked upon the completion of Mercury's Trial: Master.
 * Rewards from Standard difficulty include, which can be traded for the dragon  or the , and can be used to upgrade the Fafnir Statue facility.
 * Rewards from Expert additionally include, which alongside s can be used to craft Water-attuned High Dragon weapons with High Brunhilda's Bane.
 * Additionally, weekly clears from Expert additionally include small amounts of s, which alongside s and s can be used towards enhancing Water-attuned High Dragon weapons into tier 2, significantly increasing its power against enemies outside of High Brunhilda.

HP
HP isn't too much of a concern, as all adventurers should be able to withstand the unavoidable damage High Mercury inflicts at the beginning of the fight if they have sufficiently strong equipment, and the fight has no further sources of unavoidable damage.

Weapons
Crafting Void or Chimeratech weapons, or better, can improve your adventurer's performance (especially if it's Chimeratech) in the quest, though technically optional. Still, if possible, at least equip your adventurers with Void weapons at minimum.
 * Generally speaking, if you're able to clear Tempest Chimera Strike: Standard (and preferably, also its Expert difficulty), you should obtain materials from it to create a Chimeratech weapon, as it should be more powerful than void weapons.
 * If planning to clear Expert difficulty in auto-battle mode, weapon requirements are higher than normal due to the lower DPS efficiency. Treat all weapons as one rank lower than normal.

Dragons
Everyone should be ideally be equipped with a max-unbound dragon at a minimum.

Wyrmprints
All adventurers should equip their standard wyrmprints in normal compositions.

In an auto battle composition, adventurers may see benefit from running Strength Doublebuff wyrmprints such as or  for offense, and Healing Doublebuff wyrmprints such as  or  for survivability, due to the very high frequency of defense buffs.

DPS/Hybrid DPS
These units will be doing the majority of the DPS, and provide buffs/debuffs if applicable.

Support
These units spend most of the time buffing other adventurers.
 * Don't bring more than two pure support adventurers in the whole composition.

Healer
If desired, the healer keeps the team alive and provides support.

General Party Setup
There are two general variations of compositions in High Mercury's Trial - 4DPS and 3DPS. There are also two specialty compositions involving Templar Hope that have unusual requirements and not compatible with normal co-op.

The three real requirements for general compositions are as follows:
 * One of the adventurers in the composition must be able to heal the entire team if desired (to reactivate any HP-based abilities), and to mitigate chip damage. Shared skills and dragon skills are also acceptable.
 * One of the adventurers should behave as the close range baiter. Usually, this job falls to the weakest DPS melee role.
 * One of the adventurers should behave as the long range baiter. Usually, this job falls to the healer or buffer role.

Tidal Explosion
This is the fight's initial "HP check" blast.
 * Any adventurer with, such as , should use defensive skills such as to reduce the damage taken, though it is entirely optional.
 * Afterwards, if possible, heal it back up ASAP to restore HP conditional abilities. Winds, Protect Us! at level 3 will provide healing, but one may opt to run other skills to make it go a bit faster.
 * Shared skills can help with further mitigation and/or healing.
 * You can't iframe it, however if you are a melee character then you can hold down Force Strike to not get knocked back.
 * Sword-wielding adventurers that aren't can also attempt this sequence of actions: dodge roll towards High Mercury, attack twice, force strike, then attack five times without using a force strike. Due to knockback immunity between the third and fifth attack on the second string of attacks, they will also not be knocked back, and this also improves SP gain.
 * Lance-wielding adventurers can also attack immediately, but make sure that the attack string is ongoing (restart the string if it's about to end at the fifth attack) and do not use a force strike; lances have natural knockback immunity that is strong enough to prevent movement from the opening blast's knockback while within the string of attacks. Alternately, hold a force strike only after the fifth attack has landed.
 * Axe-wielding adventurers should just simply attack immediately without ever breaking the chain or force strike. Axes have natural knockback immunity that is strong enough to prevent movement from the opening blast's knockback.
 * Melee DPS adventurers should stand to the upper-left of High Mercury in preparation of the next attack.

"Stomp + Dash + Tail Swipe"
High Mercury will target the closest player to her and do this 3-attack combo. Once she has stomped, the direction of her dash is locked in. After the dash, she will do a wide tail swipe behind her.
 * Melee DPS adventurers should stand to the upper-left to bait the stomp, then skill, dodge, or move to High Mercury's side and continue to DPS as she dashes. After the dash is complete, adventurers that aren't baiting distant attacks should move to High Mercury's front, against the wall. This positioning of High Mercury is important, as the top corner is a safe spot that applies to all 3 variations of the "Whirlpool" attack.

"Water Shotguns x2"
High Mercury will target the farthest player and fire 2 "Water Shotgun" blasts of several balls of water. The ranged baiter should skill, dodge, or move out of the way.

"Whirlpools"
High Mercury will summon whirlpools in one of 3 possible patterns, decided at random. A consistent safe spot is in the upper-left of the map, which is why it was important for the melee DPS adventurers to bait High Mercury there earlier.

Spheres of Salvation + Stomp + Dash + Tail Swipe + Water Shotguns
High Mercury will summon 4 Spheres of Salvations (henceforth referred to as bubbles) that can be entered as safe zones. Standing inside a bubble will make the player invincible to all of High Mercury's attacks. However, if multiple adventurers try to enter the same bubble, then it will be destroyed. Each player should make sure to indicate which bubble "belongs" to them, whether by discussing in a pre-made room or by using the arrow stickers.
 * Generally, the ranged baiter will take up the third bubble from the left immediately once they spawn.

While the bubbles are up. High Mercury will perform her Stomp + Dash + Tail Swipe combo again, followed by another two set of Water Shotguns. All players should be ready to enter the bubbles before High Mercury's map-wide "Waterfall" move, which follows shortly afterwards.
 * Generally, at this point, the ranged adventurers will take the rightmost two bubbles
 * Usually, a ranged DPS such as, , and will take the third bubble from the left.
 * Usually, a healer or buffer such as or  will take the rightmost bubble.
 * If playing in a public game, it might be wise to watch the minimap for adventurers' positions and only move when you are sure you will not accidentally enter someone else's bubble.

Should a bubble be accidentally popped,  priority should be given to damaged or ged adventurers on remaining bubbles, so that they don't get killed by the next attack.

"Waterfall"
High Mercury will summon a waterfall that hits the entire map. This cannot be avoided with skill iframes, and causes severe damage. There are three methods of mitigating it:
 * All adventurers enter the safe bubbles that were summoned previously, which blocks all damage from it.
 * If some bubbles were popped, prioritize damaged or ged adventurers entering them. Healthy adventurers should have no need for these bubbles.
 * Do note that may cause adventurers to take more damage than intended; this may become an issue in teams with.
 * Dragon tank it with a dragon skill, if shapeshift is available.
 * Generally, it will be safe to tap the dragon's skill button once High Mercury finishes twirling after the "Waters, heed my command!" callout. Tapping this button too early may cause issues with certain dragons with faster animations, such as.
 * To maximize the odds of surviving this attack, buffs, damage reduction (from  debuffs,  buffs, and 's abilities), and/or a  can help.

Aqueous Prison
Shortly after the Waterfall, High Mercury will target the farthest player and put them into an Aqueous Prison. The other adventurers will then need to break the prison to free the trapped player, or they will take severe damage, and it likely will be fatal if they were already damaged and did not receive healing in time.

While the ranged baiter has been farthest from High Mercury up to now, they should instead roll toward High Mercury, while the weakest DPS moves farther away to bait the prison. Once the purple attack marker appears below that player, they should roll back to the main party to be freed. The ranged baiter should return to a far distance for the next attack.

Homing Bubble
High Mercury will target the farthest player and set a Homing Bubble to follow them. The ranged baiter needs to direct this bubble away from the rest of the party - it will deal severe damage to anyone it touches and also any nearby adventurers caught in the explosion, and it cannot be avoided with skill invincibility frames. Get away from it, baiting it away from the DPS group, until it explodes on its own, or dragon tank it.
 * Note that the reason a different adventurer took the prison earlier is so that the ranged baiter doesn't have to take both prison and homing bubble - which would absolutely end very poorly for them without some serious regen healing and defensive buffs.

"Stomp + Dash + Tail Swipe" + Water Shotguns + Whirlpools
High Mercury will do her stomp + dash + tail swipe combo again, with the Homing Bubble from earlier exploding around the time of the Tail Swipe. She will follow up with another set of Water Shotguns and Whirlpools.
 * The ranged baiter needs to be prepared to dodge the shotgun after the homing bubble ends, while also moving up towards the top-left of the map to dodge the Whirlpools.

Bursting Bubbles + Water Shotguns x3 + Whirlpools
High Mercury will walk to the center of the map and summon a circle Bursting Bubbles around her. When hit, these bubbles will split into 4 smaller bubbles with the momentum of whatever attack hit them. Shortly after Bursting Bubbles, High Mercury will fire Water Shotguns again, but this time she shoots 3 rounds instead of 2. Then she'll cast Whirlpools again.


 * The safest approach to this is to follow High Mercury to the center and hug her side, then use a skill to both pop the bubbles and iframe them.
 * Anyone who ends up outside the circle will need to iframe the bubbles when they expand outward with skills or dodge rolls. They also should not hit the bubbles, as doing so will launch the smaller bubbles into the circle and likely harm the players inside if they're caught unaware.
 * The ranged baiter needs to retreat ASAP once the Bursting Bubbles are dealt with, so they can bait away the shotguns. Remember that 3 rounds need to be dodged this time, not the usual 2. High Mercury will go back to using 2 shotguns for any future uses of the move.
 * During the 3 shotgun phase, the ranged baiter also needs to make their way around to the top-left in order to dodge Whirlpools again.

Spheres of Salvation + Summon Help + "Stomp + Dash + Tail Swipe" + Water Shotguns x2 + "Waterfall"
High Mercury will summon Spheres of Salvation again, but this time she will also summon rats that will try to destroy the bubbles.
 * Attacking the rats alone is a DPS loss - continue to fight High Mercury instead, however all players should have a dragon ready in case a bubble gets destroyed.
 * Wide AoE attack skills can help immensely with this, as they can deal damage to both High Mercury and the rats at the same time.
 * Adventurers should now consider shapeshifting now to "dragon tank" - that is, transform into their dragon and time their dragon skill such that they are mid-skill when the Waterfall hits. The dragon's timer will become depleted by the hit, but they will continue their skill animation and not revert until that animation is over. Simply being in dragon form without using a skill is not enough, as the Waterfall is a multi-hit move that will revert the dragon and likely harm (and possibly kill, if the player was at low health) the player if the dragon isn't animation-locked in a skill.
 * The timing for transforming is right after the Tail Swipe, during Water Shotguns. Then, the timing for using the dragon skill is when High Mercury spins around, shortly after she calls out "Waters, Heed my command!".
 * Generally, it will be safe to tap the dragon's skill button once High Mercury finishes twirling. Tapping this button too early may cause issues with certain dragons with faster animations, such as.

Loop A
If High Mercury is broken during any of the moves above, she will enter this loop of attacks until she is broken once more.

Bursting Bubbles + Homing Bubble + Water Shotguns
High Mercury will go to the center for Bursting Bubbles again, but will then cast Homing Bubble shortly afterwards, followed by a set of Water Shotguns.
 * The DPS group should approach Bursting Bubbles the same as before: hug High Mercury's side and pop the bubbles with a skill.
 * The ranged baiter actually should not approach High Mercury for this phase, but instead be prepared to iframe with skills or dodge rolls. Once the bubbles are popped, they need to skill or dodge the incoming Bubbles, then be prepared to bait the Homing Bubble and Shotguns away from the party.

Stomp + Dash + Tail Swipe + Water Shotguns + Whirlpools
High Mercury will do her usual Stomp + Dash + Tail Swipe combo towards the closest players, followed by Shotguns toward the farthest and another round of Whirlpools.
 * This is the same drill as before. DPS adventurers need to bait the 3-hit combo to top-left, while the ranged bait needs to dodge shotguns and approach the top-left to dodge whirlpools.

Loop B
If High Mercury is broken during Loop A, she will enter Loop B. Once Loop B finishes, she will move back to doing Loop A.

Spheres of Salvation + Summon Help + Aqueous Prison + Stomp + Dash + Tail Swipe + Waterfall
High Mercury will do a similar set of moves to the Summon Help section before, but this time she throws in an Aqueous Prison.
 * The ranged baiter should actually take the prison this time, and other DPS adventurers need to be ready to free them ASAP. One of the adventurers should instead bait High Mercury away from the prison and other adventurers - going for top-left this time actually doesn't matter.
 * The team should be ready to dragon tank the Waterfall again, transforming during either the Dash or Tail Swipe, should at least one of the bubbles not survive the rats' attacks. See the previous instance for timing information.

Bursting Bubbles + Whirlpools + Aqueous Prison
High Mercury will walk to the center of the map, followed by Whirlpools, followed by Aqueous Prison.
 * Since High Mercury does Whirlpools right after Bubbles this time, there's no opportunity to bait her to the top-left. Due to this, it is not safe to continue attacking HMC until the Whirlpools are done. The team should retreat according to the Whirlpool pattern, then needs to regroup to deal with the Prison quickly.
 * High Mercury will then resume Loop A, which starts with Bursting Bubbles again. The DPS adventurers need to hug High Mercury's side after the prison is broken, while the ranged baiter should keep some distance and be prepared to iframe the bubbles with a skill or dodging.