The Planeswalker War was a tremendous, yet mysterious war that took place on Corondor following the events in Wayfarer, shortly before the Phyrexian Invasion (4195 AR to 4205 AR).
The war was triggered by Ravidel, but included such powerful planeswalkers as Leshrac, Tevesh Szat, Kristina, Jared Carthalion, Geyadrone Dihada, and Sandruu, and probably many more.
Little is known about the Planeswalker War, due to the cancellation of Magic's line of comic books. Several characters from that conflict have yet to appear in any other novels or storylines, leading many to speculate that these characters may have perished in the war. However, this is mere speculation. Dakkon Blackblade was never a main planeswalker in this war.
Among storyline fans, the Planeswalker War is one of the most-discussed storylines that never came about.