Capcom development guru Seth Killian has shed some light on the new 'Pandora Mode' that's being incorporated into the upcoming Street Fighter X Tekken. Apparently, when a player drops below 25% health, he can choose to activate this mode as an option of last resort. The character activating Pandora Mode is instantly killed, at which point his tag-team partner has about eight seconds to win the match using a maxed-out EX meter. Once those eight seconds elapse, however, the tag team partner also gives up the ghost.
Given the brief window between activating Pandora Mode and certain death, it seems like it'll probably be most effective in deciding close matches, rather than tilting the playing field in the direction of the losing player during one-sided matches.
In a brief interview with Joystiq, Killian contrasted Pandora mode with other desperation modes from other fighting games, such as the "X Factor" in Marvel vs. Capcom 3. "There's really no disadvantage to [those modes]," Killian said. "You get them for being beaten up, but there's no disadvantage," he continued, concluding that "[Pandora Mode] has a massive disadvantage."
If you're curious how the whole "Pandora's Box" motif fits into Street Fighter X Tekken, the following cinematic trailer from TGS 2011 will fill you in.
BOOM video 10468