User blog comment:JoAlter/Invincible Iron Fist/@comment-4802891-20190811162835/@comment-25848535-20190812220113

Yes 1 turn after initiating the Np, you have to click his np card(which will become Buster) in order to proceed to attack. Because he will be fully immune to all skills and effect, then it’s always possible for him to use his np. (What about delay Stun such as Franber NP?) oh dang I forgot about that...

And yes the idea is to let him create Arts chains for others and a buster chain after.