(inky just pointed out what you're trying to do, you're trying to get rid of the storyline and return bossfights to what it was, right? Not gonna happen.)
Mr trollface: that’s what you said about Yharmin, and the scourge, and the salmon… why do I feel like everything’s a threat to the multiverse? Besides, I’m fine with eternal darkness.. I’ve learned how to play solitaire in my head!
Collector: the tyrant was trying to take over the multiverse and probably commit multiversal genocide in the process.
The scourge was attacking the citadel, which is supposed to be a safe place for travelers. Without it new travelers would be lost in the multiverse and probably die.
The salmon wasn't really that bad. I never said it was a threat to the multiverse, but it was destroying a lot of stuff in it's rampages