Here's my predictions of Roman's Interactions that could either work (Including non-datamine characters):
Original Roster & Officially Datamine[]
BlazBlue[]
- Jin Kisaragi
- Noel Vermillion
- Carl Clover
- Hazama Honoka
- Valkehayn R. Hellsing
- Bullet
- Hibiki Kohaku
Persona 4 Arena (Ultimax)[]
- Teddie
- Mitsuru Kirijo
- Elizabeth
- Yukari Takaba
- Tohru Adachi
Under Night In-Birth[]
- Carmine Prime
- Gordeau the Harvester
- Seth the Assassin
- Bloody Chaos
- Phonon the Chemeti
RWBY[]
- Ruby Rose
- Sun Wukong
- Neopolitan
- Emerald Sustrai
- Cinder Fall
Arcana Heart[]
- Saki Tsuzura
- Kira Daidouji
Senran Kagura[]
- Homura
- Hikage
- Mirai
- Miyabi
- Ryōbi
Akatsuki EN-Eins[]
- Sai
- Dawei Ye Lue
- Ernst von Adler
- Mycale (Perfecti)
Non-Datamine[]
RWBY[]
- Mercury Black
Arcana Heart[]
- Zenia Valov
Senran Kagura[]
- Haruka
- Rin/Suzune
- Imu
Akatsuki EN-Eins[]
- Marilyn Sue Dajie
Some of my reasons of him and these characters coming soon.