Aang, Elemental Adept

Whenever a creature enters the battlefield under your control that shares a color with Aang, you may choose a keyword ability that that creature possesses. Aang gains an ability counter of the chosen ability. Aang can only gain one of these counters from each color. (If a creature enters the battlefield under your control that shares two or more colors with Aang, you may pick one to use this ability.)

When Aang enters the battlefield, you may search your library for a Mountain card, reveal it, and put