Tensei Shitara Slime Datta Ken - Cover of Vol 13 .. I believe They are Trio Demons of Rimuru - Testarossa, Ultima, Carrera . looking good . Finally Empire War Arc has Begun | Facebook
Testarossa (Canon, Tensei Shitara Slime Datta Ken)/Amaterasu | Character Stats and Profiles Wiki | Fandom
Respect the Black Numbers' Generals (Tensei Shitara Slime Datta Ken | That Time I Got Reincarnated as a Slime) : r/respectthreads
Testarossa | Top-Strongest Wikia | Fandom
TESTAROSSA The White Primordial Power & Abilities Explained | Tensura Explained - YouTube