The differences of Classic Outfit/Without Shirt Panel only ends up being noticeable in Instant Kills of:
Potemkin (01:35)
Chipp Zanuff (01:56)
Millia Rage (02:36)
Johnny (03:44) (Mostly at the End)
Jam Kuradoberi (04:25) (Mostly at the End)
Dizzy (Mirror) (04:43) (Explosion flying part)
Leo Whitefang (06:50)
Ramlethal Valentine (07:17)
Elphelt Valentine (07:42)
Kum Haehyun (08:33)

I only learn about this ''classic outfit'' after randomly getting recommended video by Helio Knight :
   • GGXrdR/R2 | Dizzy Easter Egg  

This is also such a weird addition because in a real match you would literally never use this ''Gamma Ray'' attack, its need 100% of Tension Meter and deals so little damage for that cost.

Its kinda intresting that Ky Kiske & Dizzy seems to be only 2 characters to get something like this, Would be cool if they somehow found a way to also give this to Sin Kiske to complete Family Trio.

(Ky's hair falls down after losing 1 match or dealing enough damage to him.
Its program in such way that if you do Instant Kill on Ky, his hair immediately fall down so they didn't need to make 2 different reaction from Ky for every single Instant Kill)

00:11 Sol Badguy
00:33 Ky Kiske
00:53 May
01:15 Faust
01:35 Potemkin
01:56 Chipp Zanuff
02:17 Zato-1
02:36 Millia Rage
02:56 Axl Low
03:15 Baiken
03:44 Johnny
04:05 Venom
04:25 Jam Kuradoberi
04:43 Dizzy (Mirror)
05:10 Slayer
05:26 I-No
05:43 Sin Kiske
06:04 Raven
06:27 Bedman
06:50 Leo Whitefang
07:17 Ramlethal Valentine
07:42 Elphelt Valentine
08:04 Jack-O'
08:33 Kum Haehyun
09:03 Answer