Temporal Restoration

The caster creates a crystalized anchor in time that the consciousness of the caster, and up to 8 other targets, can return to upon consensus of all who were targeted (and who are still alive). 

The casting of this spell requires a precious gem worth at least 5,000gp, which is consumed in the process of using this ability.  The Gem, while activated by this spell, will glow bright light for 20' and dim light for another 20' and will be immovable (like that of an activated Immovable Rod) for the duration of it's activation, or until the spell is cast again, or until all targets of this spell who are still alive agree to return to the point in time when the ability was activated, or if there is a total party kill, or if Dispel Magic is cast on the activated Gem at lvl 6 or higher, otherwise requiring a DC 16 ability check using your spell casting modifier. (If the Gem is dispelled in this way, the targets of the ability will instinctively know that their ability to return in time has been terminated.)

Outside of the game, all who agree to submit to this spell are required to make a photocopy, backup, or duplicate of some kind that includes all of the equipment, gear, money, etc and Character Levels and Class options at the time of the activation of this spell. the DM holds these character sheets until the return ability of the Gem is activated or there is a total party kill, where upon the backup character sheets are returned to the appropriate players, while all progress in time, items, or experience gained past the point of initial activation is lost.