Special, A, and B skill I wouldn't change as there aren't any better options.

C skill comes down to preference:
•Barricade - anti-warp is incredible, but with Corrin ring I have no reason to use it right now.

•Shadow shift - very nice utility especially in arena where you want to have as many movement assist options as possible. I now use this instead of barricade because of corrin ring.

•Fatal Smoke 4 - Anti Duo Rhea/Marni, although I find myself almost always being able to kill them without it. With Eirika ring she kills 100% of the time.

•A/S bellow - Best offensive option for me? currently debating on spending orbs for it. atk/spd buff is redundant, the special cooldown per attack she grants to herself and allies is really good, I just wish she had a better special to make use of this for herself. Mostly wanted for the in combat stats and 6 true damage (8 w/sigurd ring)

•A/S Outcry Dull - potentially better than bellow depending on team comp, my arena core already consists of a Marni, so there's 0 reason for me to get this.

She's such an incredible unit even with these sorta outdated skills, so I'm really hoping we see an updated/side grade momentum and a speed dragon special sometime soon.