Nomura's set rules of time travel are fucky as hell.
Shit STILL doesn't make sense to me.
So, lemme get this straight, if anyone has their heart separated from their body at any point of their personal timeline, this makes it possible for this person at all points in time to time travel. Hearts without a body can time travel freely, but a body (with or without a heart) needs assistance. Also, I could have sworn that someone said in DDD that travel to the past was impossible with a body, yet in the Union X vid I'm watching right now, Malecifent states that time travel to the future is impossible.
Displaced bodys in time will also forget everything they've learnt upon returning, I think this may only apply on trips to the future though. There may be a limit on how long one can stay displaced.
Am I on the money, or has my brain rotted away from binging on KH all month?
I hope KH3 has a big fuckin entry on the mechanism of time travel in its glossary.