Hmm. As someone who mainly plays SR in endgame I’ll list my worst enemies to encounter. I’ll do it from the perspective of 1v1 in boss rooms, as a clusterfuck in shards with a nem is a different story.
1: Mad Queen. She’s a pain, I don’t have any chars that can dps her down before that red aura of death, and few who can tank her. So basically you always have to kite, and a misstep is death for glassier chars.
2: Grava. I don’t even hate his arcane balls. What I hate is the inconsistency of his fumble pools. Sometimes you can kill him before his de-buff, sometimes you die because you can’t leech due to fumbling all your attacks. Very frustrating.
3: Maiden. If you misplay and get blitzed by her on a glassier char, you’re dead. It’s honesty one of the more frustrating things in SR for me. Ok, so that’s a case of git gud. But no matter the char it feels like it takes FOREVER to kill her, plus she has a really annoying heal skill so it takes even longer.
4: Fabius. Simply because he can spawn with insane weapons that obliterate you no matter what. Usually he’s not a problem, but sometimes he’s impossible to kill/ he’s dealing mad damage and I rage quit after 5 consecutive deaths.
5: Theodin. Thankfully he’s rarer than annoying nems, but man this guy can hurt. Plus 2 stage in general is just frustrating in SR.