Velik's Temple HM guide (new dungeon in a ~month)

Which one? The crystals?

Well above 50% the boss is just targetting one person with purple aggro and give the circle afterwards, under 50% everyone will get it. You have to kill crystals with the circle so you can hide from the Dust AoE mechanic. Always after the Dust mechanic, new crystals will spawn in the place where you killed previous one and the new one will be always stronger than the old one. Weakest takes just 1 circle to kill, Middlle one 3 or 4 and the one after is invincible I think. Under 25% he no longer uses this mechanic.

They look slighty different
The weakest is just red floating crystal - nothing special.
Mid one is similar but has like another floating pieces (some of them look like wings) around itself
The last one is the same as previous but has like magic barrier (looks kinda like Sorcerers shield)

Look at this video:

Weakest crystal can be seen at 4:55, 5:38 or 6:30.
Mid 7:20, and the invincible (or strongest - not sure) can be spotted in background since 7:50