Your helper is already simple, it just need some fixs
;---------------------------------------------------------------
;Projectile helper
[statedef 222]
type = A
movetype= A
physics = n
ctrl = 0
anim = 230
sprpriority = 2
velset = 0,1
[State hitdef]
type = HitDef
trigger1 = !time
attr = S, NP
hitflag = maf
animtype = Medium
damage = 200,0
guardflag = MA
pausetime = 1,1
sparkno = s1
hitsound = s5,2
guardsound = s6,0
ground.type = high
ground.slidetime = 0
ground.hittime = 0
ground.velocity = 0
air.velocity = 0,0
[State to exploding state]
type = ChangeState
trigger1 = movecontact
trigger2 = vel y > 0
trigger2 = pos y > -vel y
value = 223
;---------------------------------------------------------------
;Exploding projectile
[statedef 223]
type = A
movetype= A
physics = n
ctrl = 0
anim = 240
sprpriority = 2
velset = 0,0
[state safe pos ground]
type = posset
trigger1 = !time
trigger1 = pos y > 0
y = 0
[State end]
type = DestroySelf
trigger1 = !animtime