I continue to see conflicting accounts about Itachi [New Asian Style]'s Passive 1. Here's the current in-game translation:

"Double Agent - Susano'o Enhancement: Itachi is immune to Debuffs, can have up to 5 Technique Points maximum and c*e 2 Mystery skills in a round. Whenever Itachi causes Knockdown or Low Float, increase his Attack by 15% (stackable). Whenever ninjas in your lineup causes Repulse or High Float, decrease that ninja's Ninjutsu by 15% (stackable)."

I've spoken to people on my server at different times about how the debuff portion does make him seem quite bad, but then I'd been told multiple different stories. I was told most often it was a mistranslation and he buffed instead of the Ninjutsu debuff, but then I was also told that he was changed in a patch to fix that but the translation was never updated, and others simply had no clue.

I cannot find any information about any of these claims outside of videos before his release where his skills were outlined, where the translation would say "increase" for both and not a single mention of "decrease" so I'm honestly left more confused. Please, if anyone knows definitively, tell me.

[Edit: Found the answer myself by actually paying attention and yes, yes he does nerf your team so he's very much a round 1 Ninja.]