2.2 The T in Magic: The Gathering The T stands for Test
This planeswalker can exile itself, too, which can protect it from a threatening board of attackers
Whenever you cast your second spell each turn, you may sacrifice an artifact
Decks trying to resolve one crucial spell love it, so it tends to show up a lot in decks like Scapeshift, Sneak and Show, Ad Nauseum, and Mono-Green Wave
If you manage to satisfy all four in the same turn, he transforms into an upgraded version that repeatedly generates life, cards, counters, and damage every upkeep while also discounting your spells
Discovery / Dispersal Discovery was an overpriced Preordain, which is probably good enough with the upside of being able to cast Dispersal later in the game to answer a key threat