Planeswalkers: origins and powers.

Planeswalkers, the most powerful mages in the Multiverse, these spellcasters can travel to and bend the planes.  They are few, fewer than wizards and even sorcerers, and like wizards and sorcerers, they are born with their powers.  The first planeswalker was the great wizard Alderius Silverhem, who, in 980, preformed the Ritual of the Open Veil, which was usually used to teleport things great distances.  Silverhem used it to open the Eternities between the planes, but he was sucked into the void, and was fused with a piece of it.  Alderius returned with the power to travel and control the planes, so he then learned to control his new powers, and traveled all over the Multiverse.  Alderius then settled down, married, and had children who possessed magic and planeswalking powers, then the children of Alderius grew up and married, and their children had planeswalking powers, and so forth.   The powers of a planeswalker are the ability to travel across the Eternity between the planes, and can change the planes' terrain with Truenames.  Planeswalkers are only a handful every generation, on each plane.