ReversalDefs take the HitDef parameters pausetime, sparkno, hitsound, p1stateno, and p2stateno, plus:
reversal.attr = attr_string
attr_string specifies the list of attack attributes that can be reversed by this ReversalDef. It is a standard hit attribute string. For instance, reversal.attr = SA,NA,SA means stand+air, normal attack, special attack.
sparkno = S1500, Overrides P2 hitspark
sparkxy = 0,0 The sparkxy parameter is treated as an offset to P2's hitdef's sparkxy. The MoveHit trigger can be used to detect if P1 successfully reversed P2
hitsound = S1,0 Sound upon hit
p1stateno = The stateno P1 changes to on hit
p2stateno = The stateno P2 changes to on hit
[State 0, ReversalDef]
type = ReversalDef
trigger1 = 1
reversal.attr = S,NA ;SCA,NA,SA,HA,NP,SP,HP,NT,ST,HT
pausetime = 0 ,0
sparkno = S3000
sparkxy = 0,0
hitsound = S1,0
p1sprpriority = 2
p2sprpriority = 1
p1stateno = 0
p2stateno = 5000
numhits = 1
Id = 0
hitflag = MAF ;HLAFD+-
ignorehitpause = 1
There is an undocumented "attr" parameter for the ReversalDef SCTRL, which should not be confused with the required "reversal.attr" parameter. This works similar to the attr parameter for the HitDef controller in that it will define attributes of the Reversal occuring from the ReversalDef, allowing the Reversal to be affected by an opponent's HitOverride controller if the Reversal's attributes match that of Player2's HitOverride. If omitted, the Reversal will have no attributes assigned to it, and thus will ignore the effects of Player2's HitOverrides.
You can also use the "ID" parameter for reversaldefs. Useful with gethitvar(chainid).
Additionally, there is a glitch in the Reversaldef controller which causes Player1 to retain Player2's target information even after Player2 returns to an Idle state. This allows Player1 to use target-based state controllers such as TargetState and TargetLifeAdd, as well as the Target redirection trigger, when they would normally not be allowed to. Through specific coding, it is possible to utilize this glitch to replicate a "damage-over-time" effect such as Poison.
Another good note about applying this SCTRL to helpers