Bolt Escape - Leaves behind a highly visible trail, in case it wasn't obvious where they were going with that scroll anyways. Surely your alliance has some Mist Form/Bolt Escape users as well? Or can coordinate a group to cut them off?

Bat Swarm - If 30 people are stupid enough to stand in a moderately small AoE that drains their life and gives it to the vampire, they deserve to die. Seriously - Spread out, keep your distance and use ranged attacks(notably silver bolts) and this won't be an issue. The number one thing to remember is not to stand in the huge life-draining AoE.

Bash - Costs a ton of stamina and requires pretty close range. It's only OP when combined with Broken Talon spam(which is 99% of the time, I suppose).

I dont find bolt escape OP. People have other abilities (or bolt escape as well) to chase someone and mana doesnt last forever as well. In fact i find it a nice tactical feature. Especially squishy mages have a good way to get away when the situation is tense, which i really like.

Bat Swarm - Pretty obvious that wiping dozens of players at a time by permanently staying in this ultimate is broken.

Mist Form - Mana cost is ridiculously low, some vampires out regen the cost while in combat and in the form. Way worse than bolt escape, at least you can catch a bolt escape user. Vampires you just sit and watch them stay immune right before your eyes.

Roots in general need a Immunity timer in which the root ability doesn't apply at all, I wouldn't want to still get hit by Dark Talons but still be able to move while getting hit by Impale x7.

I also feel interrupts CC animation needs some sort of temporary immunity, you can still stop an ability and put it on GCD but don't have the exaggerated stagger animation go along with it every single time.