Dude ...

It's really easily countered with a healer or genjutsu mirror or immune status buffs

Sleep can be annoying for low levels.

Sleep, along with chaos, can be carried onto the next round if the timing was right. Your problem is the Haze clone; it ensures SB's sleep always goes last or second-last, which could make the debuff lasts longer. It also not affected by Taunt, so rip whoever you put in front of SB.

But...

Sleep can be deflected by Genjutsu Mirror. It is dispelled if you got hit with Taijutsu moves. Or a simple cleanse could get rid of it.

Sleep is kinda good against low-level MBs who haven't unlocked their RoW yet.

A fully awaken Kurenai is good enough to counter low-level SB. Cleanse, debuff deflect and heal. Or maybe the Earth Pains team to cleanse debuffs?

yes lets nerf the fire main who gets nerfed every update cause its not like lightning doesnt need a nerf or water or even earth no lets nerf the guy that keeps getting nerfed

to be honest his kits are just too good, hard to balance

Sb needs to be furthermore nerfed for the only reason that his kit is too good together with p2w ninjas.

Imho it will be perfectly fine if some of those passives/mysteries would change depending on the lineup you are running for example 4th mystery should be as is now but if you use masked man or itachi susano'o then should cost 40 chakra to be used.

OP Did you just you know decide to let your opponent put you to sleep? I mean it isn't like its a prompt or anything.

lol i know right

Then here are some more OP skills:

Water Main: Neurotoxin, Acupuncture, Poison Tai, and Healing Tips

Wind Main: Flower Guard, Giant Rasengan being done twice, Shoot Down Rasengan being done twice, Wind Dance, and Dance of Impetus,

Earth Main: Shields galore, immobile, interruption, and Pose of Duel

Lightning Main: Root of the Warrior, Blood Thirsty Demon, ANBU Tactics, Acupuncture, Paralysis, Tag, and Calm Mind

Trust me, every class has something that is OP. It is not just the Fire Main.

The issue is that itachi susano'o, masked man, onoki lineup with sb, for example, doesn't get countered by an equivalent pay to win azure fang lineup with lower initiative as it should, instead, be, since fire should be weak to water).