Compendium mechanics

[Allexan]

When I get a new persona, do I have to visit Velvet Room for it to be added to the compendium, or can I discard it during the same run and still summon it afterwards?
I'm talking about brand new personas, not the ones you have to manually overwrite.

[Steel]

They get registered automatically the first time you encounter them and add them to your party.
To be clear, this means that yes you can discard them and summon them later.

[J.M.]

No need to visit the velvet room but when your party is full, do not discard the new persona you just get. It has to be in your party to be registered so delete one that’s already in your party.

[Terra]

Unless they changed it, they are added to your compendium once they ENTER YOUR ROSTER, not when you recruit them.

Like, if you have a full roster and have to choose one to discard, discarding the one you just got WILL NOT add it to the Compendium. It's only when you end a battle with it in your deck that it gets added.

[♋Phenex]

Yep made that mistake in the beginning by deleting the new persona instead of replacing one in the party.

Not the worst though since money is pretty easy to get later on and you can fuse basically anything not locked behind something.