Yawgmoth (God of Phyrexia)

Yawgmoth's powers and abilities

God of Phyrexia - Yawgmoth seized the plane of Phyrexia for his own, becoming a being made of pure black mana in the process. Due to his new stature, Yawgmoth gained a slew of new abilities, most notably a nearly infinite mana supply, omniscience and omnipresence while on the plane itself and nigh-omniscience elsewhere. This awareness allowed him to effortlessly combat enemies that could both teleport and manipulate time.

Corruption and Disease - Even before becoming the God of Phyrexia, Yawgmoth had a penitence for diseases, cooking up devastating plagues wherever he went. With his new form, this ability went further, allowing him to create plagues specifically for individual races or populations. He also spawns a type of corruption known as Phyresis that slowly maddens those that come into contact with it and slowly turns them into metallic abominations.

Durability - Yawgmoth proved virtually invincible even against the might of the most powerful planeswalkers in the multiverse, shrugging off their most powerful spells with ease. In the end, he was only defeated through a series of events that disconnected him from Phyrexia, being hit by a condensation of white mana (his weakness) capable of destroying a plane and then being struck by a weapon made up of some of the most powerful artifacts in the multiverse that had been charged for a thousand years. And after all of that, his spirit still existed and began reforming itself as a corruption in Urborg.

Death Cloud - Yawgmoth's entrance onto a plane is already an extinction level event, but the Death Cloud he can spawn is the truly devastating ability. This cloud of pure death makes whatever it hits uninhabitable and is capable of killing nigh-unkillable planeswalkers. Anyone caught in this cloud will also return as a loyal servant of Yawgmoth.

Mind Control - Yawgmoth exerts a steady and constant mind controlling effect around himself, powerful enough to break the most powerful planeswalker in existence, Urza, who had been readying himself for this conflict for a millennium.

Avatars - If Yawgmoth chooses to deal with a situation personally, he can instead create an avatar to carry out his plans. These vary in power based upon the amount of mana he puts into them.

Plane Creation - Although he is not a planeswalker, Yawgmoth found a solution to invading other planes by creating artificial planes, such as Rath, and forcibly crashing them into another plane to transport himself and his armies.

Phyrexians - Yawgmoth has legions of his Phyrexian abominations to call on at all times. Although an individual Phyrexian is variable in power, his legions are perfectly capable of conquering entire planes for their lord and should not be doubted. They also spawn his Phyresis corruption and can lead to victories turning into defeats as armies turn into the very things they were fighting.

Yawgmoth's weaknesses

Pure White Mana - Although Yawgmoth is completely immune to most attacks, his sole weakness lies in pure white mana that is uncorrupted by other sources.

Becoming Unmoored - If Yawgmoth's connection to Phyrexia is severed, his mana pool becomes finite.