If one of the tokens somehow is under another player's control as the delayed triggered ability resolves, you can't sacrifice that token. It remains on the battlefield indefinitely, even if you regain control of it later.
Lamentation
If the target creature is an illegal target as Lamentation's first ability tries to resolve, it won't resolve and none of its effects will happen. You won't gain life.
If an effect stops a token from attacking a specific player, that token can attack any player, planeswalker, or battle, or not attack at all. If the effect stops the token from attacking a specific player unless a cost is paid, you don't have to pay that cost unless you want to attack that player.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Lars Grant-West
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
