Karn (Pre-Mending)

Karn's powers and abilities

Oldwalker - Karn possesses an original planeswalker spark (which he inherited from Urza), allowing him to freely travel between the planes of the multiverse without being erased by the Blind Eternities. With this spark, his magical abilities were also elevated to the point where he could be considered a god by many. His physical form became a matter of will, enabling him to regenerate it infinitely (rendering almost all damage up to and including complete disintegration meaningless) and he could shape it into whatever he desired. Because of this, Planeswalkers possess an incredibly high resistance to all damage types and only the most powerful of beings could hope to harm them in any meaningful way with most battles between Oldwalkers taking months or longer to draw to a conclusion. Karn can also summon mana duplicates of allies he has enlisted throughout his journeys.

Urza's Master Piece - Karn was constructed by Urza initially to serve as a being capable of traveling through time with no ill effects. His original silver body is nearly indestructible and inside of it are Xantcha's Heartstone, the Weakstone and the Mightstone. The Hearstone gave him his sentience and the twin stones give him immense power over the world around him, allowing him to empower and weaken almost anything.

Planebuilder - Karn built the artificial plane of Argentum (later Mirrodin and then New Phyrexia) with his magical abilities and then used the Mirari (a powerful reality warping probe he had made) to create an overseer for the plane.

Metal Magic - Karn primarily utilizes colorless magic to power and create artifacts and machines (although he can use all colors of magic). He is able to pull and create metals out of the aether and make any device he can imagine. Karn is also able to time travel at will among a litany of other abilities.

Karn's weaknesses

Pacifist - Karn is a staunch pacifist and will not get into a physical confrontation unless he absolutely has to. This unwillingness to fight can cause him to hesitate when action is needed.