I just wanna make sure i got it right.

In the example, they say you do 4/12, then stop. Then join a new raid doing PP. after defeating him, you get saved to Festergut and Rotface too. Is this because u need to kill Festergut and Rotface to kill him, or because the raid killed them?

would i get saved to Dreamwalker to if the raid killed her before i joined? she isnt required to kill PP, but optional to do before him.

another example, what would i get saved to if the raid i joined was going for Sindragosa, i had done 4 first, and the raid i joined had killed all others except for Sindra and LK