need help with merc

the red merc who says barydians strike true, she heals way too fast. it has same voice actor as another merc with very fast attack rate and speed aura (which im currently using), and it does a lot of blood skills.

even if i stand still i cant do more damage than the healing. i used this merc many times before at lower levels, its really good, but at level 70+ the healing is faster than i can damage. furthermore my strategy is to use split arrow from a distance so i cant stand still to keep doing damage, i die very fast if merc is on same screen as me. how do i slow or maybe stop the healing?

also another question. the merc that summons a big fallen emperor and various ghosts, and keeps saying "power divine", he's not spawning for me anymore. i need this merc the most because the summons help out a lot for bosses. my current one is level 62 and too low level. how do i get this merc to spawn again?