I used this kind of trigger when I wanted to prevent a move from happening or activate the tag system in my roster. My self-insert can't call WereGarurumon for Assist with QCF+kick if WereGarurumon's his partner in simul matches.
Example of the code
[State 0, VarSet]
type = VarSet
trigger1 = Partner,name = "WereGarurumon by TGM" && partner,authorname = "DarkWolf13-MvC2"
trigger2 = Partner,name = "WereGarurumon by TGM" && partner,authorname = "DarkWolf13"
trigger3 = Partner,name = "WereGarurumon"
var(29) = 1
; NEW !! Tag active definer
[State -2, def]
type = VarSet
triggerall = Partner,Authorname = "mouser-MvC2" || Partner,authorname = "DarkWolf13-MvC2"
trigger1 = teammode = simul || teammode = turns
trigger1 = roundstate < 1
trigger1 = time = [0,1]
var(33) = 1
[State -2, def]
type = VarSet
trigger1 = partner,Authorname != "mouser-MvC2" && Partner,authorname != "DarkWolf13-MvC2"
trigger2 = teammode = single
trigger2 = roundstate < 1
trigger2 = time = [0,1]
var(33) = 0
