They're taking a lot of liberties, but so far, but Robin and Elise both use actual tomes found in their native games (we only got to saw Leo get bodied, so lol).
But speaking of Robin and Elise, they seem to be doing template moves for similar types of units. I noticed that Cordelia and Hinoka shared some moves, but I wasn't entirely sure, but now I see Robin and Elise both use the same kind of electric orbs for their basic moves. That's a bit disappointing. Hopefully this changes depending on equipped weapon or something.
Also, I must have missed Takumi's wind sword. I watched his part of the demo, but I don't recall him using that.