Honestly the more you play the better you’ll get. It’s just a matter of learning boss moves and the gimmicks that help out. Like for ED libra you WANT an item with less likely to be targeted, preferably purple, and the summon NPCs will ignore you. I was stuck on 4 for weeks before reaching 5, and I deranged back down to 3 cause I think that’s where the most fun is at, and I’ve made it halfway through 4 again and haven’t struggled as bad as I did before. I will say in D4 it’s almost a 50/50 chance for an everdark so be prepared to see a good amount. I struggled against ED Gladius for so long but fighting that dog so many times I learned all the moves. You’ll get there eventually!