Finish BG helper leaves a black box in screen? #noob questions

[swanky]

So being the idiot that I am I wanted to add some Hyper Combo Finish BGs to Mystique (with their AI patch) - for personal usage, of course, not to be redistributed.
Idea:
Having a check in Statedef -2 spawn a helper that removes itself when Roundstate >3, so that it doesn't get spawned multiple times (and thus spawns multiple sound effects and explods).
So the order in which things are progressing is HyperBG gets cancelled into HyperBG glass breaking BG helper which removes itself with !time. Hyper Combo Finish BG helper gets spawned in, lasting until end of roundstate 3.

I had to change the Hyper BG defs in order to have that background get removed when the hyper finish background triggers, which is working.
[State 40001, Glass Break]
type = ChangeState
trigger1 = root, stateno !=[3000,3302]
trigger2 = WinKO
trigger3 = p2life = 0 && roundstate = 2
trigger4 = root, NumProjID(3010) >= 1 && WinKO
value = stateno+1

It's only mostly working, however, once the explod gets removed I have a big, transparent box in the background. Having the helper destroyed by a time trigger may spawn the helper again when Mystique is in her animation for a long period of time (like her Statedef 3000 hyper), and I don't want that. Now... how do I set that right?

Thanks for helping a rookie :>



[State -2, Winhelper]
type = helper
triggerall = NumHelper(4001)=0
triggerall = ((stateno = [2999, 3302]) || (Numhelper(3101) = 1) || (Numhelper(3102) = 1))
trigger1 = WinKO
trigger2 = p2life = 0 && roundstate = 3
name = "WinKO BG"
ID = 4001
stateno = 4001
pos = 0,0
postype = left
facing = 1
keyctrl = 0
ownpal = 0
supermovetime = 9999
pausemovetime = 9999
ignorehitpause = 1



[Statedef 4001]
type    = S
movetype= A
physics = N
anim = 9999 ;blank animation


[State 4000, AvX No BG]
type = assertspecial
trigger1 = time <= 120
flag = noBG
flag2 = noFG

[State 4000, PlaySND]
type = PlaySnd
trigger1 = time = 0
value = 1500, 25

[State 4000, Background]
type = Explod
trigger1 = time = 0
trigger2 = numexplod(4001) = 0
anim = 12700
ID = 4001
pos = 0,0
postype = left  ;p2,front,back,left,right
removetime = -2 ;doesn't get removed correctly at the end of its animation, interestingly, even though it's non looping in FF
pausemovetime = -1
supermovetime = -1
scale = .85, 1
sprpriority = -5
ownpal = 1
ignorehitpause = 1
bindtime = -1

[State 4000]
type = removeExplod
trigger1 = time > 120
ID = 4001

[State 40003, DestroySelf]
type = DestroySelf
trigger1 = roundstate > 3