In the case of Liliana, Heretical Healer, the first part of resolving the trigger is to exile her, then return her to the battlefield transformed. However, since the trigger is from the Liliana that was on the battlefield, it is looking to exile that Liliana from the battlefield. Once Liliana hits the bin, she’s not going to be exiled, let alone come back transformed. Because of that “if you do” clause referring to her transformation, that also means you won’t get a 2/2 Zombie token. Essentially, it’s the same result as if she hadn’t triggered at all.
This also means that if an opponent has a Liliana, and they have another creature die, you can destroy Liliana in response to the trigger that would exile her, and thus prevent the trigger from doing anything!
Today’s Rules Tip written by Jen Wong