beside that suggestion above, you can lurk into the char's CMD and if that char uses winane's AI method, you can remove any parts of the CMD code like:
;-| AI |------------------------------------------------------
[Command]
name = "CPU1"
command = U, D, F, U, D, F
time = 0
[Command]
name = "CPU2"
command = U, B, F, U, D, F
time = 0
[Command]
name = "CPU3"
command = U, D, D, U, D, F
time = 0
[Command]
name = "CPU4"
command = U, F, U, B, U, D, F
time = 0
[Command]
name = "CPU5"
command = B, B, B, U, B, U, D, F
time = 0
[Command]
name = "CPU6"
command = U, D, B, U, B, U, D, F
time = 0
[Command]
name = "CPU7"
command = F, F, B, U, B, U, D, F
time = 0
[Command]
name = "CPU8"
command = U, D, U, U, B, U, D, F
time = 0
[Command]
name = "CPU9"
command = F, B, B, U, B, U, D, F
time = 0
[Command]
name = "CPU10"
command = F, F, B, B, U, B, U, D, F
time = 0
and
[State -1, Activate AI]
type = Varset
triggerall = var(59) != 1
trigger1 = command = "CPU1"
trigger2 = command = "CPU2"
trigger3 = command = "CPU3"
trigger4 = command = "CPU4"
trigger5 = command = "CPU5"
trigger6 = command = "CPU6"
trigger7 = command = "CPU7"
trigger8 = command = "CPU8"
trigger9 = command = "CPU9"
trigger10 = command = "CPU10"
v = 59
value = 1
Then obviously erase all the controllers like, example:
;ATTACKS
[State -1,PUNCH]
type = ChangeState
triggerall = statetype = S
[b]triggerall = (roundstate = 2) && (var(59) != 0)[/b] ;<---- this trigger here means this is an AI controller
trigger1 = random = [0,1300]
trigger1 = p2movetype != A
trigger1 = p2bodydist x <=20
trigger1 = statetype =S
value = 200
trigger1 = ctrl = 1
trigger1 = time = 0
Just make a backup before doing it, though.
If it's using different methods, I don't know how to help you.
Or else, you can make those chars weaker by just editing their [Data] values (from their CNS file).