I'm sure plenty of people will agree with at least some of these, so here I go. I want to discuss current bosses that need to be nerfed and buffed (mostly nerfed).
NERF:
Set 1
Cave Johnson - Grenades are very powerful in comparison to his SH counterpart. They instant kill anything and afterburn can kill heavies
Dr. Octagonpus - Chainlighting should be nerfed to tails'
Pacman*
Bonk Boy - Overall just extremely cheap. He doesn't deserve the soda popper he gets when he rages. It's just OP
Kirby*
Woody - Saxton Hale with global rage
Set 2
Dr. Who - If he couldn't collect ammo for his diamondback, he'd be more balanced.
Fox - Rage shouldn't be global if he becomes ubercharged.
Bart - Saxton Hale with global rage
Conker*
Rayman*
Franky - Rage gives stun, chain lighting, AND a shotgun?
Set 3
Donkey Kong - The yellow screen that pops up when he rages lasts too long. It blocks your view COMPLETELY.
Weeping Angel - Tele and rage builds too quickly.
Darth Vader - Chain lighting, uber, and detonator with rage. One should be removed
Sonic - Chainlighting should be nerfed to Tails'
Wankers*
Set 4
HEROBRINE - Unarguably most OP hale of all time. Summons 2 dead people with each SJ. He's so fun I'd be okay with him staying the same. Still, OP as fuck
Set 5
Skelescout* and can kill heavies in one hit
MeeM - Can kill heavies in one hit
Set 6
Rage Sniper - Can kill heavies in one hit and collect ammo for his rockets.
Dic Soupcan*
Abe - Rage is global AND he's fast. Nerf one of the two
*DRUGS RAGE. EVERYONE hates these rages and they simply last too damn long. I think they should be removed all together, or nerf other aspects of these hales.
BUFF:
Set 1
Radigan - Rage is underpowered. Takes extra damage when brass beast is deployed
Wall-E - Weak shortcircuit, slow, and a huge hitbox
Set 4
Cuddly Heavy - No stun at all with rage
I may be wrong on some, but I've asked others and together this list was made. Hopefully we'll see some action.