原文Once you've finished casting Ancestral Communion while you control your commander, its first ability will trigger. It doesn't matter what happens to your commander after that. However, if you control your commander as you start casting Ancestral Communion but don't control your commander by the time you finish casting it (perhaps because you sacrificed it to activate a mana ability), Ancestral Communion's first ability won't trigger.
原文If you have more than one commander (thanks to a partner ability, for example), controlling one of them when you finish casting Ancestral Communion is enough to satisfy the trigger condition of Ancestral Communion's first ability. If you control both, you'll still only create one copy of Ancestral Communion.