>>4445421
Apparently they already have Hastur in Requiem. He's bound to Euclid.
As for other Lovecraftian entities I would like to see Cthugha's mother (Tulzscha) and daughters (Aphoom-Zhah and Fthaggua) come to mind. Also maybe N'tse-Kaambl pulling a Van Gogh and possessing Athena after forcing Athena to possess Medusa would funny.