黄昏の群れ操り

クリーチャー・トークンが１体戦場を離れるたび、黄昏の群れ操りの上に＋１/＋１カウンターを１個置く。{2}{W}, 黄昏の群れ操りの上から＋１/＋１カウンターを１個取り除く：飛行を持つ白の１/１のスピリット・クリーチャー・トークンを２体戦場に出す。

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: Create two 1/1 white Spirit creature tokens with flying.

Crimson Vow Commander

Duel Decks: Sorin vs. Tibalt

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.

Ravnica: City of Guilds

Whenever a creature token leaves play, 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 into play.

Salvat 2005

If Spirit tokens created by Twilight Drover leave the battlefield, they will trigger its first ability.

If a player leaves a multiplayer game, all creature tokens that player owns also leave the game. Twilight Drover's ability will trigger once per token.

Note that Twilight Drover doesn't have any way to sacrifice tokens or otherwise cause them to leave the battlefield.

The first ability only cares that creature tokens leave the battlefield. It doesn't matter where they went.