the math is the basic one for poison in general so the damage is a basic fixed 1999 per stack that gets modified only by the single enemy resistance.

(to be clearer: your ninja ninjutsu doesn't modify it in any way, nor does it do it the enemy damage reduction, only resistance).

poison tai just add the poison debuff to every ninja tai standard attack in your lineup.

thanks for the info pal

There is a limit dmg of poison tai.

I'm pretty sure it's 1999, therefore at max 4 stacks poison tai damage won't exceed 7996.

It's still a lot to go for 3 rounds if you don't cleanse it.

The "secret" from the loading screens says its based off your ninjutsu. But still has a hard cap.

Hi there! I don't know much about this math thing since i hate math, and i'm not sure but based from what i've read and seen and experienced .. It is based on, i guess, Ninjutsu of the Caster which is the AzureFang and the Resistance of the receiver of the poison, thus calculates the overall damage that poison debuff will do .. Just like with the Ignition status debuff ..

no otherwise lvl 1 water main OS everything with her poison skill ... which not the case ;D

In my opinion which can or cannot be right.

If you look at poison fog wave (Water main - 1st mystery)
it says "poisoning causes ninjutsu damage to the maximum life percentage"

I have pretty low 48k power (lvl 83)
when I was fighting with enemy "A" (55k power, lvl 87) poison dealt to him 4.8k dmg at 4 stacks - target Iruka approx. 11k HP
meanwhile in fight with enemy "B" (63k, lvl 91) poison dealt 5.4k dmg at 4 stacks - target Iruka approx. 12k HP

both had pretty much same lightning blitz team
"A": Lightning, Iruka, Asuma, Danzo
"B": Lightning, Iruka, Asuma, Darui

therefore my conclusion is:
- poison deals 10% HP per stack (up to 40% in total)
- poison stacks have hard cap of 1999 dmg per stack (up to total 7996 dmg)

Resistance or Ninjutsu will not play a role in this. But as I said, this is my opinion.

Ninjutsu and Resistance does provide a role. You don't see yourself dealing max poison damage at low power against people who have far more power than you.

Ninjitsu does take effect, it is azure fang's ninjitsu. Resistance also take effect.

Poison is capped at 1999 damage per stack, up to 4 stacks can be applied.

There is no percentage life limit. If can kill a 7k max hp ninja from a much weaker player instantly with poison if you can somehow put 4 stacks on it without it taking life damage. (For example, the opponent spam shields and non-debuff clearing heals on the ninja.)

Under normal cir*stances, you will not reach 1999 damage per stack. You will only reach it when you are fighting someone way weaker than you.

Heres an experiment for you to try, use poison tai, face someone with a kabuto stack the poison on the kabuto and one of his clones equaly, see which takes more damage at the end of the round from poison. I've done this so the answer is the kabuto takes more damage from poison even though mysteries will hit harder vs clone. So clone has less resistance but takes less poison damage and your saying ninjutsu matters?