The jutsu is just cheap as fuck. It has a low CD, it sucks chakra from a huge area, it slows, it has no drawbacks, and snakes can basically do anything (jutsus, punching, resting) while doing this except walk. Taking 10% of your opponents chakra per second is op. For one, you can't even kill a Snake in 10 seconds, so basically if they just stand there with this jutsu for 10 seconds they take all of your chakra and you are fucked. Period. There's this guy who spams it as his primary jutsu, and man is it annoying. I constantly fight him with no chakra, which is practically impossible. Oh yeah and he heals from it. Damn! That's just too many benefits for one jutsu.
I suggest making the aoe much smaller and increasing the CD a bit. a GSW size 10% chakra stealing per second aoe, that heals you and hurts your opponent is better than the 3rd Iron RB passive. It needs to be a much lower range. Maybe the range of dragon flames or something. I think if this was fixed then Snake may finally no longer be the clear best clan in the game.