Ugin

King Kai probably learned the spirit bomb from this guy

Ugin, the spirit dragon, is one of the 3 planes walkers that sealed the Eldrazi. He is probably the multi-verse's foremost expert on the eldrazi. Before the mending, Bolas used his +3 to defeat him and tortured the information on the Eldrazi out of him. Ugin died shortly there-after. Except he didn't, because Sarkhan Vol used Ugin's Nexus to travel back in time! Wizards "doesn't" take character death "lightly" because they "want" deaths to be "meaningful," so "don’t" expect this type of stuff to happen whenever they feel like bringing a character back to life [1]. It wouldn't be too surprising if Sarkhan Vol become's Ugin's minion, in large part because Ugin is a dragon. Sarkhan Vol had followed the orders of Ugin's ghost after all. Ugin's home is Tarkir.

Morph

Ugin taught morph magic to humans, to help them not get wiped out by dragons. So not a total bag of dicks like most MTG dragons (Looking at you Bolas).

Balance

Ugin is an environmentalist. He likes the ecosystem to be balanced, even to the extent he advocated sealing the eldrazi instead of killing preserve any ecological balance they might be a part of. He thinks both humans and Dragons are important in Tarkir.

In Play

As everyone expected, Ugin is the second colorless planeswalker to be printed by WotC. He has 3 abilities. His +2 bolts (well, actually ghost fires) a target creature or player. His -X is a excellent board sweeper (unless the permanents your opponent cares about are colorless, so pretty useless against affinity) but also a double edged sword, if you aren't careful you can end up hosing your own dudes. And his ultimate, a −10, is almost the exact opposite of Nicol Bolas's ultimate. With Ugin's ultimate you get to gain 7 life, draw 7 cards, and then cheat up to 7 permanents onto the battlefield. He is expensive at 8 colorless mana but any half decent ramp deck can push him out fairly quickly. The fact that he is colorless and can integrate in any deck is also a major boon.

Planeswalkers of Magic: The Gathering
Original Five:	Ajani Goldmane - Chandra Nalaar Garruk Wildspeaker - Jace Beleren - Liliana Vess
Alara:	Elspeth Tirel - Nicol Bolas - Sarkhan Vol - Tezzeret
Zendikar:	Gideon Jura - Nissa Revane - Sorin Markov
Scars of Mirrodin:	Karn - Koth of the Hammer - Venser
Innistrad:	Tamiyo - Tibalt - Davriel Cane
Return to Ravnica:	Domri Rade - Ral Zarek - Vraska
Theros:	Ashiok - Kiora - Xenagos - Calix
Tarkir:	Ugin - Narset
Kaladesh:	Dovin Baan - Saheeli Rai
Amonkhet:	Samut
Other:	Dack Fayden - Vivien Reid - Kaya
Commander 2014:	Daretti - Freyalise - Nahiri - Ob Nixilis - Teferi
Pre-mending:	Bo Levar - Commodore Guff - Jaya Ballard - Urza
Forgotten Realms:	Ellywick Tumblestrum - Bahamut - Lolth - Zariel - Mordenkainen
Planeswalker Groups:	The Gatewatch