I'd like her Strong Attack (X) to become her dash attack. Her second Y+X combo, where she does a back flip using her weight to bring down the Giant Blade in front of her (whilst facing backwards herself) makes for a good F Tilt or F Smash.
The piledriver move? You mean that swirling aerial attack of hers? That would work well indeed! I thought of it as a N Air, but that Up B could work to and makes her a little different from Ike and Cloud indeed.
D Air is also easy to pull from Hyrule Warriors, it's her last combo attack, I think it's a strong attack where she pillars down the Giant Blade into the ground, making a sort of shockwave.
U Tilt could be that one kick of her victory animation, kind of similar to Ganondorf's current U Smash, but obviously faster and far less powerful. Sends her foes up straight upwards.
D Tilt could be the slide she finishes her regular combos with. This is kinda what Cloud also does however... Shouldn't really be all that much of a problem right?
AAA is what I said the regular YYY attack, with a rather strong finisher.
U Air is her strong attack in the air, not the Aether-like attack but how she swoops her sword upwards. Kinda only is one move in her move set in HW that does this.
D Smash could be where she slashes the ground, and make a burst of water come out of it, having prety good vertical knockback. It's her Weak Point Smash attack basically.
F Smash could be somewhat like Link's, where she does a double attack by first hitting opponents with her sword lightly, then follow up with a jumping attack where she attaches her sword to her feet. Second attack would be more powerful, and is rather fast as well but has some lag afterwards.
U Smash is where she swings her sword overhead, like she does with her Special attack (pressing A).
General stats:
Weight: Marth/ Lucina's
Running speed: Sheik's
Fall speed: Ike's
Air speed: Zero Suit Samus's
Traction: Cloud's
Air acceleration: Luigi's
Kinda think a moveset writes it's own here. Really not much which can go wrong.
And for the haters who keep on claiming there's no spin-off based moves in the game, Mega Man uses that one uppercut that was from a crossover game, so there's that. Am not knowledgable about Mega Man otherwise, so that's the only info I got about it. Besides, Hyrule Warriors did great on all systems, and is STILL doing great.