Phlegethon has chaotic godlike power in a small black kitty body. His normal feline frame couldn't hold it so he has bio tech self growing 'armor' developing around him all his life to hold it all in.  He 'bleeds' sliver metal liquid if someone breaks the armor. It also grows back, its fully apart of his organic body.  

He appears to many who summon him as a 'hero' ready to help them but leaves most worlds in misery and ruin seeing mortals as play things and his 'toys'.  His secret weakness is being bound by the 'rules' of the rune markings that hold together his armor. If he isn't careful someone who knows the secrets can control him.