Scans from V-Jump have surfaced showing a group of all the characters as well as detailed pages on Sephiroth, Kefka, Cloud and Terra in which Sephiroth’s EX Mode appears to be the one-winged style of Advent Children and Cloud’s has him wielding the Ultima Weapon from FFVII. Another scan shows Leviathan and a Bomb.
(Thanks to Dark & Divine.)