I’m really surprised that no one is saying Spider Gwen. After her rework, she was built to destroy the collector. Her evade is better than Sparky’s once his specials are unblockable, she starts the fight with extra charges which means extra Attack with no ramp up necessary, her heavy attack slows him so he can’t go unstoppable when he’s low, and she can enervate him to sometimes throw in extra hits without risk of special attacks. She was a huge help when I had to fight the collector over and over when I went for Elder’s Bane.