The following character packs for BlazBlue: Cross Tag Battle were just revealed at EVO 2018.
Character Pack 4 ($4.99)
Mitsuru Kirijo (Persona 4 Arena)
Merkava (Under Night In-Birth)
Character Pack 5 ($4.99)
Mai Natsume (BlazBlue)
Akihiko Sanda (Persona 4 Arena)
Yuzuhira (Under Night In-Birth)
Character Pack 6 ($4.99)
Nine The Phantom (BlazBlue)
Labyrs (Persona 4 Arena)
Mika (Under Night In-Birth)
Along with those packs, the trailer also teases another franchise to be added to the series. If earlier rumors and datamining is to be believed, this will end up being Senran Kagura.