Essence of theDemon Emperor

You gain the form of a demon emperor, ruler of Hell with a design generally up to you. This form is supernaturally powerful and outstrips almost any mortal or immortal for that matter in raw attributes and a host of other abilities up to you based on the form you take. Regardless you could beat gods to a bloody pulp as you are now.

Perfect memory with infinite storage as well as agelessness.

Gain dominion over the seven deadly sins, can use them in a variety of ways including conceptually.

You are a font of pure corruption, a walking source of impurity, disease, pain, misery, all the evils of the world are at your disposal. You are able to twist, corrupt, taint, and pervert anything you get your claws into to your hearts content. As a side effect you are immune to corrupting or purifying effects.

Able to create and summon all sorts of demons to serve you, whether they be Imps to the lords of hell themselves. These demons are oathbound to be loyal. You can corrupt others into demons and resurrect the dead into demons. You can have any demons you create able to access your Hell. Other demons and demon like creatures will see you as something of profane divinity on an instinctual level.

Have your own personal Hell that you have total control over. Whether it be a classic fire and brimstone with wailing souls of the damned, or just a blank void. You can transport yourself too and from it instantly and appear anywhere within said realm. Things brought into this hell can be imprisoned and sealed away or tormented by your demons, really whatever fate you may wish upon those unfortunate enough to fall into your grasp.

If you manage to be slain somehow you will revive a day later within your Hell.