[quote=TwilightDragon]
Okay. Something with Grima.Ideas?
[/quote]

Well, we really don't need to bring Grima himself back. Assuming we go with Chrom sealing Grima away, villain just has the blood of Grima and just trying to wipe out the exalt line to prevent the blood of Naga from screwing with things again in a thousand years? He/she/it can be a necromancer and spam Deadlords at our party or something.