>>23513995
Everything that's listed.

Grausam
Insania Rex
Lapis Lacrima
Yaiba
Gearworm
Arachne
Bullet
Legion
Gaze
Hex & Insomnia Rex
Soma
Centurion
Void in the Garden
Immortal Void
Grausam RT:α
Grausam RT:β
Cybele
Cybele RT:α
Cybele RT:β
Lapis Lacrima RT:α
Lapis Lacrima RT:β
Gunfort
Gunfort RT:α
Gunfort RT:β
Dreadnought
Dreadnought RT:α
Dreadnought RT:β
Rebellion RT:α
Rebellion RT:β
Eclipse

If there's anything else to fight, I wouldn't know about it.
Keep in mind, there might be a second encounter with him somewhere. There are two 'complete' sets in the files. I mean fully modeled with proper icons and everytihng.
(Picrel) The left is Zeruchweiss and dropped by this encounter. The right is Zeruchrot - no clue where it's from but it being completely finished unlike the other undiscovered sets which are missing icons and shit, this is probably in the game right now.