Actually I have proven Ulti is from the future using very strong ingame evidence. This is evidence I have reorginized from post #534 of the "1572" thread:

1.) Odine says she is from the future, we can assume he tells the truth, since there is no evidence or motive for him to do otherwise.

2.) Odine obviously doesnt have the JME yet or else Squall and co. would destroy it, so it must be made in the future.

3.) Ellone only has the power to "teleport" BACK in time NOT FORWARD. In the whole game Ellone never goes forward in time ( she cant ), thus Ultimecia MUST be reaching BACK for Ellone as she cant go forward since Ellone doesnt possess that power. If she did, it would have been shown undoubtedly.

So, Ulti is undisputably from the future
WAY TO GO, I'm with Noj_R