The power of his blood and his semblance would take over him there from a unknown source. When Cosmic Slasher is in this form, he would likely be more powerful his strength and speed and even his semblance too. When he loses his sanity, he wouldn't be using his weapon there but his fingers of knowing the claw martial arts, for his semblance would be dark purple and would be surrounding his body as well. His aura would then be used as a weapon there that he can make fire shots, explosions, energy attacks, and be able to deal more damage with it coated to his hands. Since his blood of the orochi has done this and also infected his semblance and his treasure called the Draigen Soul Gem, he becomes a dangerous monster on the inside. So whenever you see him in remnant, make sure to notice if he isn't in purple colors or he would get you.