just add an enemy, name = "nameoftheenemy" as a trigger to the anim/snd you want

EDIT: you have to add the name exatcly as it is in the def file,

no, it's not a standard. There is a plnety of ways to do it.
Try to do this way: create a changestate and trigger it like that:

[State lol, Changestate]
type = ChangeState
trigger1 = !Time
trigger1 = enemy, name = "whateveristhename"
value = 191 <---- here you wrote another statedef
ctrl = 0

then you have just to create another statedef specially to this special intro, anth in this statedef create a changestate to Statedef 0.

I actually do different. I'm posting my code bellow, so if you can try to do like me too.

Code:

;===============================================================================
;INTRODUCTIONS
[Statedef 190]
type = S
ctrl = 0
anim = 190
velset = 0,0

;=================================COMMON STATES FOR ALL INTROS
[State 190, VarSet]
type = VarSet
trigger1 = !Time
v = 4
value = floor(Pos X)

[State 190, AssertSpecial]
type = AssertSpecial
trigger1 = 1
flag = Intro
flag2 = nobarDisplay

;=================================NORMAL INTRO 1
[State 190, ChangeAnim]
type = ChangeAnim
triggerall = !Roundstate
triggerall = !Var(1)
trigger1 = enemy, name != "Raiden"
trigger2 = enemy, Name != "Big Bear"
trigger3 = enemy, Name != "cvsraiden"
trigger4 = enemy, name != "cvsmika"
trigger5 = enemy, name != "mika"
trigger6 = enemy, name != "R.Mika"
trigger7 = enemy, name !=  "Mika"
trigger8 = enemy, name != "cvseagle"
trigger9 = enemy, name != "Eagle"
trigger10 = enemy, name != "ixnaydk sakura"
trigger11 = enemy, name != "ixnaydk rock"
trigger12 = enemy, name != "ixnaydk owl"
trigger13 = enemy, name != "ixnaydk ryu"
trigger14 = enemy, name != "ixnaydk terry"
value = 190

[State 190, PlaySnd]
type = PlaySnd
trigger1 = anim = 190
trigger1 = animelem = 2, =0
trigger1 = random >=500
value = 190,0
channel = 0

[State 190, Helper]
type = Helper
trigger1 = Anim = 190
trigger1 = animelem = 13, =0
helpertype = normal
name = "Cape"
ID = 7000
stateno = 7000
pos = 0, 0
postype = p1
facing = 1
ownpal = 1

;=================================INTRO VS RAIDEN
[State 190, ChangeAnim]
type = ChangeAnim
triggerall = !Roundstate
triggerall = !Var(1)
triggerall = enemy, authorname = "Hh"
trigger1 = enemynear, name = "Raiden"
trigger2 = enemynear, Name = "Big Bear"
value = 191

[State 190, PosSet]
type = PosSet
trigger1 = !Var(1)
trigger1 = anim = 191
trigger1 = !Time
x = 40*(facing*-1)

[State 190, VelSet]
type = VelSet
trigger1 = Anim = 191
trigger1 = animelem = 40, =0
x = -abs(pos x - var(4))*.057
y = -5

[State 190, VelAdd]
type = VelAdd
trigger1 = anim = 191
trigger1 = animelem = 40, >=0
y = .55

[State 190, StateTypeSet]
type = StateTypeSet
trigger1 = anim = 191
trigger1 = animelem = 40, >0
statetype = A
movetype = I
physics = N

;=================================INTRO VS RAINBOW MIKA
[State 190, ChangeAnim]
type = ChangeAnim
triggerall = !Roundstate
triggerall = !Var(1)
trigger1 = enemy, name = "cvsmika"
trigger2 = enemy, name = "mika"
trigger3 = enemy, name = "R.Mika"
trigger4 = enemy, name =  "Nude Mika"
value = 192

[State 190, ScreenBound]
type = ScreenBound
trigger1 =  anim = 192
value = 0

[State 190, PosSet]
type = PosSet
trigger1 = anim = 192
trigger1 = !Time
x = 300*(facing*-1)

[State 190, VelSet]
type = VelSet
trigger1 = anim = 192
x = const(velocity.walk.fwd.x)

[State 190, VelSet]
type = VelSet
trigger1 = anim = 192 || anim = 193
trigger1 = ((Pos X*(facing*-1)) <= (Var(4)*(facing*-1)))
x = 0

[State 190, ChangeAnim]
type = ChangeAnim
trigger1 = anim = 192
trigger1 = ((Pos X*(facing*-1)) <= (Var(4)*(facing*-1)))
value = 193

;=================================MECH INTRO 1


;=================================MECH INTROS: VEGA
[State 190, Helper]
type = Helper
triggerall = Enemy, name != "Vega"
trigger1 = Var(1)
trigger1 = !Time
helpertype = normal
name = "Vega's Intro"
ID = 8090
stateno = 8090
pos = 30, 0
postype = p1
facing = 1
ownpal = 1

;=================================CHANGE STATES
[State 190, ChangeState]
type = ChangeState
trigger1 = anim = 191
trigger1 = (Vel y >-Pos Y)
value = 103

[State 190, ChangeState]
type = ChangeState
triggerall = anim = 190 || anim = 193
trigger1 = !AnimTime
value = 0