Buy @ TCGplayer
When Sengir Autocrat enters the battlefield, create three 0/1 black Serf creature tokens.
When Sengir Autocrat leaves the battlefield, exile all Serf tokens.
If Sengir Autocrat leaves the battlefield while its first ability is on the stack, its second ability triggers and exiles any Serf tokens that happen to be on the battlefield, and then its first ability resolves and gives you three Serf tokens.
Sengir Autocrat’s last ability exiles all Serf tokens, not just the Serf tokens its first ability created.
