There could be more than one way to make it so the armor disappears after frame 15.
One way is to change the armor into a blank state and undo the nothitby.
The other way would be to kill the helper.
I'd think it'd be easier to kill the helper. So edit the ChangeState that brings the helper into state 902. Add in the trigger to check what P1, the root, is doing. You want it gone if it's not in 210? Add that as a trigger. And you want it gone if it's in State 210 but the animelem > 15, so add that as a trigger also.
What do you mean by 1 layer? Like only one hit has reduced damage?
That's what I did before:
[State 800, 5]But the armor will be there after the state ends and there will be no way to remove it. That's why I have to replace it with root,stateno = 0 (as placeholder).
type = ChangeState ;This is so when you die or when more than one of these helpers exists, it'll destroy itself. You can add more triggers if you want. For example, a burst mode with super armor that is activated when var(50)=1. The burst mode and super armor deactivate when var(50)=0. You would want to put a "trigger3 = var(50)=0".
trigger1 = parent,life = 0
trigger2 = parent,numhelper(900) > 1
trigger3 = root,stateno = 210 && time > 15
And yes, I mean how to make the armor only take 1 instant of damage so multi hit attacks can still bypass the armor.