Aside from the chosen 1v1, all 47 players will have to face Dahu. This is considered a thrash mob.
There are some new mechanics added, but this is still a very simple fight.
For Dahu, there isn't an enrage timer, so it's best to play it safe. Every mechanic you get hit will still apply the same debuff, and 3 debuffs results in DOOM.
For Dahu, we will only include the important mechanics that needs slight explaination.
Dahu will start cleaving either left/right, and immediately followed up by cleaving the other side
To resolve:
Stay front/back of boss, and move into the AoE after it goes off.
Stay very far from the first hit. As long as you don't get hit by it, the second cleave will hit away from you. (Not recommended though, might be too far from Boss and get hit by other mechanics)
Callouts: Crossover
4 players will get a numbered marker. Dahu will target you with a fireball, killing any ads that got hit by it too.
To resolve: Marked players move to their respective waymarks the moment numbered marker appears. Wait for the fireball to hit you and kill the ads before coming back.
Callouts: Numbers
Multiple baited puddles. Move out of it.
Dahu dash x2. Stay away from where he is facing, but stay close to the end of his second dash.
Firebreath. Stay close to Dahu to dodge it easily.
Spit Flames, numbered players run to your respective waymark.
NOTE: Ads are dashing causing line AoEs to appear. Dodge the line AoEs then run immediately to your waymark.
Cross-over. Move into the first AoE.
Knockback into a safe spot
Merry-go-round. 5 conal AoEs rotation
NOTE: The second conal AoE will be the safe spot already
E.g. North -> East -> South -> West -> North
Ads will spawn and tether to MT. AoE them down, while healing the MT.
NOTE: Another tank can provoke to hold Dahu temporarily while MT is holding the ads. Not necessary though
Puddles + Ads dash + Crossover. Dodge the puddles and the ads dash near Dahu, and dodge the crossover
Spit Flames. Numbered players move to respective waymarks to kill the ads
Knockback with 2 tanks having flare marker. Tank flares get knockback to waymark 2 & 4, everyone else gets knockback to waymark 1 & 3.
Ads dash + Merry go round. Run back to middle after knockback to solve this.
Crossover
Dahu Dash x1/2 + Firebreath
NOTE: Dahu might only dash once, so standby to run if you see the AoE appear after the first dash.
Mechanics loop till dead, or party wipe.
1 Chest Coffer
Forgotten Fragment of Loss
Forgotten Fragment of Deception (Lucky!)