The only thing I'm struggling with is finding the mist dragon during Deep Fog myself. The DPS have been fine and indom handles so many mechanics on its own it's not even fair. The guaranteed damage isn't bad, and the new 8-point AoE marker reminded me of Light Pillar so I picked it up asap. You can also game the prey breath mechanic to ensure you don't get a puddle underneath you in order to minimize movement.
It seems like the window between when the dragon appears and when it does the AoE charge is smaller than it ought to be. Or the game tries to pick a spot you won't see. I don't know if sprint would last for both charges but running around the edge of the arena constantly feels like the best option.