Lilynouch

I've noticed his damage reflect was doing about 1500 damage to me (to HP directly) so I just needed to keep my hp 100% full all the time and watch out for the DR animation.

I went with 2 other friends but we could kill it fine after we started noticing the DR pattern and keeping HP high.

It does no more damage than the amount of health you have if your health is less than its damage range.

For instance, if I have 1600 health, it will do 1600 damage to me. If you have 1553 health, it will do 1553 damage to you.