His form is made up from the phantom ruby prototype embedded into his eye; Infinite made him in his and Shadow’s image because he wanted Ultimate to be as strong as possible (to be a sort of weapon) and Shadow was the only other person he could think of (with great distaste). Ultimate is a daddy’s boy who follows every order Infinite gives him, proving himself to be a major threat with the help of his phantom ruby prototype inhibitors that allow him to cause illusions- although not to the extent of Infinite because of the fact that most of the ruby’s powers are going into keeping his body stable.
Infinite is the one that named him Ultimate, because Infinite was the ultimate mercenary and Shadow is the ultimate life form, he thought the name was clever. Shadow is yet again unknowing to the making of his own son, but this time it’s not Boom Shadow. Shadow, while he didn’t ask for Ultimate to be born, is still willing to help Ultimate be something other than an evil goon. Ultimate however would never take an opportunity to betray his father (despite a small part of him that wonders), so he’ll stay evil.
Ultimate’s basic personality is edgy and sadistic, thoroughly enjoying the pain and hatred of his enemies and taking any chance to psych them out and play with their head. Getting a bit flirty at times too 🤭
