A few more details about Project X Zone (or Project Cross Zone) come from an interview with Famitsu. Tatsuya Kitabayashi from Capcom explained Chris Redfield and Jill Valentine were selected from their side because Resident Evil: Revelations was on the Nintendo 3DS.
Picking characters from the Shining series for Project X Zone was puzzling, Kensuke Tsukanaka from Namco Bandai said, but they settled on Shining Force since that has the biggest name recognition and selected characters from EXA because they felt they were the best fit. Cyrille and Toma from Shining Force EXA will represent the series. Yuri and Estelle from Tales of Vesperia were chosen to represent the Tales series because they’re older and closer in age to the other characters. Tsukanaka also said the character list is not final and there will be hidden characters as well.
Details about the battle system are unclear, but most characters are in pairs. Sanger Zonvolt from Super Robot Taisen fights solo and Ulala from Space Channel 5 is teamed up with Shining Force characters.
Characters will combine their signature moves in Project X Zone. Ryu and Ken from Street Fighter do a Shinku Hadouken & EX Hadouken. Another move combines Ken’s Shoryuken with Ryu’s Metsu Hadouken. X and Zero from Mega Man X can use moves like X-Buster & Z-Saber and Raijingeki & Twin Slasher. Kurt and Riela can use an Anti-tank lance & Light of the Valkyria. KOS-MOS and T-elos from Xenosaga have attacks like STORM WALTZ and X BUSTER & S SAULT. Yuri and Estelle combine artes to make Savage Wolf Fury & Holy Light. Kite and BlackRose use Data Drain from the .hack series.