Theodore

I honestly disagree with this tearlist, there is no best tree and there is no best vault hunter, it heavily depends on who is playing them, for example people like me who have experience with melee can kick *ss with Amon and for us they are S tier but for others Harlow is the best tor the traditional siren experience as opposed to the actual siren.

Despite being just some random on the Internet one apt nerf to the mentioned vampire bat would definitely be to heavily nerf it's healing as well as just adding more weapons and gadgets.

Your opinion is just wrong, it is a very fun game, and while it doesn't have much it still has much left for it as it only came out recently and vampire survivors wasn't as big and amazing as it is now off the bat, they will likely nerf the bat's healing and also add some more difficult missions and improve the AI, it is new and has much growing left to do so back off because a game doesn't have to be hard to be fun, and this game is very fun.

Some of these are possible with a bit more creativity.

Quicksilver: higher move speed and a focus on close up multi-hitting moves as if he is using superspeed to hit you a lot quickly and a time slow ultimate.

The Wasp: allow them to use their shrinking as a purely mobility option that lets them be more of an assassin that pops up, gets ya, then shinks down before they get executed with a big mode ultimate.

Nick Fury: have a big focus in his moveset on Shield tech and using the shield hellicarier to call in care packages and use it for a massive Bombardment ultimate.

Some of these could be easily done

Spot: don't have his spots passively block attacks but rather make it one of his abilities or even his ult.

Mephisto: A unique moveset that changes based on what characters are on your team.

Modok: can't be headshot or you have to hit the gem to headshot him.

Red skull: they are a villain, likeability is the last concern, plus the trolling would be in character and make sense thematically.

King Pin: don't just be a cloberer but also allow him to use his status to summon minions to help him in the battle, so he could beat you up or send his minions to distract the opponents or swarm them to give an opening for teammates to attack.