Teysa, Orzhov Scion

Sacrifice three white creatures: Exile target creature.
Whenever another black creature you control dies, create a 1/1 white Spirit creature token with flying.

Ravnica Remastered

"Spend your life betraying me if you wish. I'll simply take it up with your ghost."

RNA Guild Kit

You may sacrifice Teysa itself to help pay for its first ability, but Teysa dying won't cause its second ability to trigger. Any other white and black creatures you sacrifice to pay for the first ability will cause the second ability to trigger.