In life Demon was nothing but your everyday Uchiha. That changed when Riku, under the control of Trev, took his life in a fight. By instructions of his leader the body was brought to Trev where he was then resurrected by Edo Tensei, being yet another addition to Trev's army. Somewhere along the line of shinobi time, Demon's use as an Edo Tensei continued as he was brought under the control of a mad-man Uzumaki known as Keitō.
Demon spent much of his time training in the ways of the Uchiha. By an early age, he had already mastered Fire Release ninjutsu, the natural affinity of Uchihas. Eventually, he would activate the sharingan and through training, brought it to the third tomoe. The Uzumaki with his eyeball collection properly planted Sharingan of the Mangekyō form into his eyes, granting the zombie a plethorea of new hacks in the system. Most specifically the space time ability of Kamui.
Having a full mastery of Water and Wind Release, Demon was eventually able to use the notorious blood release of the Yuki clan. However, by the time of his death, he gained little mastery of the techniques and can only use it in the broadest sense.