Demonic Leviathan

The Demonic Leviathan was a planeswalker who fought Nicol Bolas in Dominaria millennia ago.

History
A few years after the Elder Dragon War, Nicol Bolas fought a demonic-leviathan planeswalker on the still-young plane of Dominaria. The fight lasted a month, reduced Madara to a third of its original size, and created the first temporal rift. In the end, the dragon relied upon his touch to defeat his foe. After the battle Bolas feasted on the remains of the leviathan over the course of a year, absorbing its power in the process. When he finished, naught was left besides what eventually became known as the Talon Gates and an assortment of blubber.

Planeswalkers met

 * Nicol Bolas

Planes visited

 * Dominaria