Are you trying to ask for a spell that does 1000+ damage and doesn't have a cooldown timer? That you can just cast as many times as you like? Because the game isn't going to let you do that without some kind of other penalty or "slowdown mechanism".
You already have Flare. It costs all your MP. And then Foul, which requires you to keep your fire/ice state running.
It's not freely usable, because that would remove the point of it.
You build up to it, and you finally get to unleash that "exciting high-damage skill" at a critical point.
If you could use your high-damage skill every turn, it wouldn't be high-damage any more, it would just be your normal damage output - and everyone else would be set to a similar power level.
Who needs to be jealous? We have Deathflare already. It's prettymuch a Mini-Ultima (blue glowing beam explosion) and we get to cast it once a minute.
For the record: AoE damage, 400 on the first enemy and varying down to 200, and you need to have built up your gauge and be in Dreadwyrm Trance (reliant on 1-minute-cooldown aetherflow skill) to use it.
We can't be sure of that.
- The 'tagline' at the end of 4.56 mentions travelling across "time and space" - though it's worth pointing out that Minfilia uses this phrase both times we meet her in the Aetherial Sea, which doesn't clearly involve time travel.
- In the trailer voiceover, the Enigmatic Figure says "how many years have come and gone? How many years have I waited for [you]?"
- given who the Enigmatic Figure actually is (or highly resembles), there would probably need to be a larger time-gap between the last time we saw him, and his current state, than whatever "real time" has passed in the game since then.
- In the Fanfest keynote, Yoshida highlighted the fact that there seems to be something odd about the Crystal Tower, time-wise - that an identical copy is present in the First despite being allegedly built 7000 years after the shards were split from the Source. And a slide in another presentation (I only saw it posted here, so not sure of the exact context) where they'd deliberately hidden parts of the text about how old it was.
This could be time OR space acting strangely, but it doesn't rule out time travel.