The Puppeteer

Flash
When The Puppeteer enters the battlefield,
target creature an opponent controls gains
indestructible while you control The Puppeteer.
At the beginning of a player's upkeep, that player
gains control of that creature and untaps it. At
the beginning of a player's endstep, put a broken
thread counter on The Puppeteer, then if The
Puppeteer has ten or more counters on it, destroy
it and exile that creature.