I runed some tests with Ninjutsu *ion , Attack *ion and Injury and I can say they are working fine. They boost damage but I can t find a formula or how it "*es" the defensive system of an opponent because it work against Damage reduction too and those stats are like equivalent values so I think they nullify each other. But if the opponent has little damage reduction a massive Tai/Nin *ion will show a big advantage to the possessor. I mean by Ninja tools or red chakra rune gates.

We don t know even more how base stats are acting too. It seems they aren t working so fine. Like I tested 14k Ninjutsu damage against a 6k Ressistance player several times and I did just 4 - 5k damage and a max of 8k crit damage. And normal should be a difference of 8k ( keep in mind that player has no elemental ressistance stats ). Beside it we don t know how ressistance or defense work as well. Is a big question still in doubt from the beginning of the game.

ignition gives only 1999 certain max damage depending in nin stat, poison can stack till 4 or 5 times i think so your test about posion damage is irelevant. And about that damage which You refer to TAI *ion i m in doubt... Because that stat either counted first time either was just purely damage randered by tai and nin itselfs. Untill damage calculation formula would be known anything is in a big shadow.