Twilight Drover

Whenever a creature token leaves the battlefield, put a +1/+1 counter on Twilight Drover.
{2}{W}, Remove a +1/+1 counter from Twilight Drover: Put two 1/1 white Spirit creature tokens with flying onto the battlefield.

Whenever a creature token leaves the battlefield, put a +1/+1 counter on this creature.
{2}{W}, Remove a +1/+1 counter from this creature: Create two 1/1 white Spirit creature tokens with flying.

Tarkir: Dragonstorm Commander

Crimson Vow Commander

Converge - Return up to X permanent cards from your graveyard to your hand, where X is the number of colors of mana spent to cast this spell.
Exile Uncle's Musings.

Duel Decks: Sorin vs. Tibalt

Ravnica: City of Guilds

Whenever a creature token leaves play, put a +1/+1 counter on Twilight Drover.
{2W}, Remove a +1/+1 counter from Twilight Drover: Put two 1/1 white Spirit creature tokens with flying into play.