Should Amaus get his buff, the best way to get rid of it is with abilities that deal high stagger damage (and grenades that deal high stagger damage, if you have them).
It’s not the end of the world if he gets this buff, as even with the extra time Lost Ark Gold takes to get rid of this buff, you should still be able to kill him before he goes Berserk.
Kaishur is the second and final boss of the Forge of Fallen Pride dungeon. Like Amaus, Kaishur has two main mechanics to worry about, except one of his is, indeed, a dreaded one-shot mechanic that will wipe your entire group.
Periodically, Kaishur will raise a defensive red shield around him. At this point, you and all your party members should stop attacking him until the shield goes away.
If he takes sufficient damage from your party while counterattacking, he will slap your whole group back with a very heavy-hitting strike. It won’t necessarily one-shot you guys, but it can certainly kill you if you’re not at full health.
Let’s move on to his one-shot mechanic. Twice during the fight, once at his sixteenth health bar and once at his eighth health bar, Kaishur will move to the center of the map and start channeling his massive attack. When doing so, pay attention to the color of the orb he is holding up; it will either be red or white. At the same time, he will also summon two phantoms; one red and one white.
You must kill the phantom that corresponds to the color of the orb the central Kaishur is holding up, and you should do so fast. Once you kill the correct phantom, a circular safe zone will spawn on its corpse that all of you should stand in to prevent getting wiped.
Don’t worry about accidentally killing the phantom of the incorrect color buy Gold Lost Ark. It doesn’t matter if it dies, so long as the correct one also does in time for Kaishur’s one-shotting shockwave.