Absolute minimum buffs for weak heroes until you figure out what to do
Peacekeeper: Unblockable top heavy finisher
Cent: Feintable unblockable finisher. No GB punish on a missed jab
Warlord: A bit more damage on fullblock lights
Highlander: 500ms defensive lights
Jormungandr: bashes deal 5 damage
Shugoki: Charged shoulderbash recovery on missed hug. A little more stamina.
Orochi: Unblockable heavy finishers
Shinobi: Unblockable heavy finishers
Nobushi: Unblockable heavy finishers. Unblockable heavies from hidden stance.
Aramusha: Less stamina usage on zone, second part softfeintable into top light.
Nuxia: A little wider trap activation.
Zhanhu: +2-3 damage on some moves
Would it solve the game's current problems? No
Would it break either of the characters above? No
Would they be strong enough to be considered on pair with the current top picks? No
Would this make the game a little better for the players who picked either of those heroes? Definetely
This game is not under development, not in beta. It was sold years ago, during the time you are making patches, people keep playing it. Minimal patches like this should come monthly. Yes, overbuff and overnerf is a risk, but it would only last for one month, not for years. Last year, you have shown with Lawbringer, Raider, Hitokiri, Jormungandr, Shinobi and Zhanhu that it doesn't really matter how much time you take, the quality and quanity is still poor during your reworks. At least then you could do it quickly.