"The Engine"

I vote to keep it simple, Eorzea Engine.

Why does it even need a name?

Unless its being sold as a marketable product can't it just be the engine?

The engine that could

Mailbox Engine

The Miracle Engine

Because in order to succeed we need that one special miracle.

I like the Phoenix or Legacy engine. :)

Le Engine with Cheese

How about, "Magi-Tek" or "Aetherwryte"

Simply "Phoenix" or "Legacy" would suffice as names :D

I think naming the engine as a form of rebirth or raising of the dead is bad, since it's implying to bring something back when said engine should be looking to the future and not the past. Something as simple as "Fantasy Engine" could work because the idea behind 2.0 is to make it as FF as possible by adding in homages from past games that people can look at and say "oh hey crystal tower just like FF3, or magi-tek armor just like ff6" and get the Final Fantasy feel.

If people see something like Rebirth engine or Phoenix engine they'll most likely chuckle and think "oh they are raising this mmo from the dead" rather than "Oh this is the new beginning for the mmo"