BUG - Progenitor Mimic copied on the stack died improperly to state-based actions when copy and original copied two different legendary creatures

SITUATION
-Volo, Guide to Monsters exists on the battlefield under player's control
-Player plays Progenitor Mimic without another Shapeshifter in battlefield or graveyard zones
-Volo triggers and makes a copy of Progenitor Mimic on the stack
-Token Mimic selects a legendary creature under another player's control and enters successfully
-Card Mimic selects a different legendary creature and enters, then immediately dies to state-based actions

Reproduce the listed Volo and Progenitor Mimic sequence, focusing on the token and card copies choosing different legendary creatures. Start by tracing how those cards enter and how state-based actions are applied; done means the behavior matches the intended result for this scenario and is covered by a regression test.

Written by the indexing model from the issue text.