I am not even sure if his buff works, just like Edo Hanzo when he was in 3v3 arena, he was bugged and broken af, and as far as I am using him with multiple mains, I haven't noticed any 40% increase in my def and res, I can't really tell if it works at all, I mean...c'mon...40%, it's a lot, but I feel like it's not even there, all ninjas take damage like before.

In theory, if I understand correctly, everything stacks with Main ninja buffs, no matter if equal %, but it doesn't stack if the same ninja gives same field buff, or different ninja gives same stat % increase. I tried with Earth Main too, and I still wasn't sure if it worked, but it *s and it's not 40%, or it doesn't work at all.