Which random characters do you hate fighting?
By random, I mean characters not known for their defensive prowess, but for some reason you always mess up due to their animations, specials, forgetting a part of their kit, etc.
For me, I'd have to say Jane Foster. I can never remember how to dodge her sp1, and then I panic about her stun mechanic so much I promptly get hit, stunned and killed. I also hate fighting Yondu, and regularly screw up trying to dodge Yellowjackets sp1. I used to mix up Fixit's sp1 with abominations and try to dash in after the headbutt only to get shot, and it took me a long time to get used to not doing that.