No record :-(
After you killed the mobs, use the Mistlock Singularity to reset cooldown then the teleporter to enter the boss area.
Put down a at the start and open it after triggering Mai Trin before you
Mai Trin is protected by ten stacks of Captain's Shield, each stack reducing her incoming damage by 10%. The only way to remove stacks is by pulling her into electric fields from Horriks alternating projectiles. Standing in the electric field will remove one stack per second from her. The fire field projectile from Horrik can be reflected and absorbed. You can easily recognize the projectile type from the icon above the targeted player.
Your Druid should be able to stay in most of the time and keep the party alive, although the amount of conditions and damage can make it difficult to hold the line. Immediately resurrect downed players.
Every 25% health, Mai Trin disappears and additional enemies will spawn while fiery cannons start shooting. Switch your damage to Horrik and deal 25% of his health to make Mai Trin return. Cleave the spawning mobs during downtimes.
Keep in mind that with each phase more cannons start shooting at you, the fight can get quite chaotic in the last phases. Luckily Mai Trin won't have any protecting stacks below 25%, so make sure to finish her rather than Horrik (Killing Mai Trin finishes the fractal).
Use against the multitude of projectiles.
You can block Horrik's cannon projectile with (Greatsword 4).
Trait and use for additional condition clears.Also change to to reduce incoming damage from spawning mobs every phase and use (Staff 5) against the cannons.
You can run Spellbreaker to counter the enemy boons and destroy the snipers projectiles at 25% with .