Planeswalker

In some works of fantasy, a planeswalker is a person with the ability to travel to different planes of existence.

Magic: The Gathering

In the fictional multiverse of the Magic: The Gathering collectible card game, a planeswalker is a powerful mage, able to travel across the planes of existence. All players are planeswalkers; non-player planeswalkers are described in Magic’s back-story (which is represented in novels, starter-deck inserts, online articles and card flavor text); and with Lorwyn the first Planeswalker cards were introduced.

Only those with a rare and innate ability called the "planeswalker spark" can become planeswalkers. (The spark can be transferred from one being to another, but the process is highly dangerous and potentially fatal.) Only one individual in a million is given the spark. Even then, they must "ascend", which usually occurs spontaneously during a time of great stress (most common being a form of horrendous death, e.g., the sylex blast or its aftereffects). This ascension, as well as the extraordinary amount of power at their fingertips, drives almost all planeswalkers insane over time. In an attempt to prevent this, most planeswalkers are tutored by older ones. Wilders, or planeswalkers that decide to travel the multiverse untutored, exist (Ravidel) but are often extremely dangerous and sometimes utterly insane.

A planeswalker has complete control over his or her physical appearance, and does not physically need to eat, drink, sleep, or even breathe (although some, such as Urza, do these things to help preserve their sanity). Planeswalkers are very difficult to kill and can't die of natural causes, or being stabbed, or even dismembered. This is due to that fact that a Planeswalker's spark is present within his or her brain, is the source of the Planeswalker power. While the brain still exists, a Planewalker still has the ability to trasverse the many planes, can regenerate and shapeshift at will, and can stay alive for millennia upon millennia—and, of course, perform magical activity.

Due to their near-immortality which radically alters their perspectives and personalities, Planeswalkers rarely have relationships with non-Planeswalkers. They know, as soon as they meet someone, that they will outlive them, and that they will have to live with the loss. However, some Planeswalkers, such as Urza, may associate with mortals if he or she finds an advantage in doing so. Urza made two exceptions, one for Xantcha (an artificial Phyrexian human loyal to him), and Barrin the master wizard, who had learned to magically reverse and control his aging. Both Xantcha and Barrin eventually died, though not of old age.

During the Time Spiral cycle of novels (which includes Time Spiral, Planar Chaos, and Future Sight), a series of rifts in the actual fabric of multiverse has begun to cause havoc and apocalyptic destruction in many planes. Specifically in the plane of Dominaria, Planeswalkers have begun to seal those rifts to repair the rents in time and space, whether according to their will or not, by giving up their Planeswalker sparks (though it usually demotes them to the status of mortals or kills them outright)—called "mending." Though it seems that the worlds of the multiverse have begun to heal because of this mending, it is revealed that all the tears in the multiverse result from entropy due to world-scarring events such as the Dominarian Apocalypse, but also because of the Planeswalks of powerful Planeswalkers—which have gradually accumulated over time.

Thus, the creation of Planeswalker sparks has been irreversibly altered by the powers that govern the multiverse. The result is a new breed of Planeswalkers, sometimes called "neowalkers," "planescrawlers," or "jumpers" by fans because of their exponentially decreased powers. These new Planeswalkers can Planeswalk between the multiverse's many planes but do not have the other advantages of the old Planeswalkers. Though they have a small boost in power, the new Planeswalkers are no longer immortal and must rely on their own wizarding abilities, rather than gain the magical might and potential that was immediately gained by their older counterparts.

By the end of the novel Future Sight, in Dominaria, several of the prominent Planeswalkers have been destroyed and some new look Planeswalker have appeared, such as Venser, a artificer living in fear on the island of Urborg and Radha, a Keldon elf.

Famous planeswalkers from the Magic mythos include:

The Nine Titans

In a last-ditch attempt to stymie the Phyrexian invasion of Dominaria, nine planeswalkers entered the plane of Phyrexia, in gigantic titan engines of Urza's design, to set off bombs to destroy the plane.

Bo Levar
Commodore Guff
Daria
Freyalise
Kristina of the Woods
Lord Windgrace of Urborg
Taysir
Tevesh Szat
Urza

Others

Arzakon
Dyfed
Faralyn
Fatima
Feroz
Fiers
Geyadrone Dihada
Glissa Sunseeker (She possessed the planeswalker spark, but lost it before it could be awakened in her)
Jaya Ballard
Jared Carthalion
Jeska
Kaervek
Karn
Kenan Sahrmal
Leshrac
Liana of Minorad
Manoj
Meshuvel
Radha
Ravi
Ravidel
Sandruu
Serra
Slobad
Teferi
Venser

the unnamed dragon-planeswalker who created Phyrexia

The Elder Dragons

The elder dragons Arcades Sabboth, Chromium, Nicol Bolas, Palladia-Mors and Vaevictis Asmadi once were powerful planeswalkers. They fought a large war entitled the War of the Wyrms or the Elder Dragon Wars. They lost their spark, except Nicol Bolas, when a powerful world spell cast all other dragons to the land, creating the elder land wyrms.

In the Guildpact novel, the dragon wizard and parun of the Izzet guild Niv-Mizzet battles against ancient deities called the Nephilim. When the fight seems to turn against him, he claims he has become bored with it and flees, never to be seen again. This has led some to believe that Niv-Mizzet is/was a Planeswalker and has left Ravnica (the plane where Guildpact is set) entirely.

Mistaken for planeswalkers

Though they are often confused for planeswalkers, Yawgmoth, Mishra, Memnarch, Jodah, Lim-Dûl and Marit Lage are, in fact, not.

"Gods"

Some planeswalkers are considered to be gods by the inhabitants of the planes. On the other hand it is uncertain if some of the known gods are really planeswalkers. Examples of these are:

Gabriel Angelfire
Gaea
The Ebon Hand
The Hand of Justice
Kaldra
Kjeld
The Myojin
Leitbur
Svyelun
Tal
Thelon
Torahn
Tourach

Some characters are considered gods, but certainly aren't planeswalkers

Yawgmoth, neither god nor planeswalker
Ramos
the primeval dragons Rith, Treva, Darigaaz, Dromar and Crosis

Cards

In the 2007 expansion set Lorwyn, planeswalkers were introduced as a new card type, distinct from artifacts, creatures, enchantments, instants, sorceries and lands. A planeswalker comes into play with a number of loyalty counters (indicated in the bottom right of the card) and can use one of three abilities each turn. Each ability costs or generates loyalty. Planeswalkers cannot attack or block. As of Lorwyn, five planeswalkers have been printed with one in each of Magic's five colors.