Lord of Vermilion Re: 2, the card collecting arcade game that brought Ragna the Bloodedge from BlazBlue and Kyo Kusanagi from The King of Fighters together (screenshots here), has another unlikely crossover. Black Rock Shooter, leads from Nier, and characters from Type-Moon’s Witch on the Holy Night are in the same game.
Black Rock Shooter
Kaine and Emil from Nier
Alice Kuonji and Aoko Aozaki from Witch on the Holy Night
The Lord of Vermilion Re: 2 update also adds Yuno, a guest from Lord of the Apocalypse, who you can get if you register a retail copy of the game with Square Enix members.
Baron, Don Quixote, and Shizuka Gozen are new familiars.
Popular familiars Anata and Cybele return along with a quest to slay Nidhogg.