Celica -atk, +spd: build help?

I have the exact same IVs for her. What I'm thinking is giving her the +atk seal (just to soften the bane a bit. Don't really have any other unit that needs it at the moment) and building her around the effect of Ragnarok (Renewal 3 as B-slot). I also run an Ardent Sacrifice Ryoma (-hp/+atk), so it's going to be relatively easy to keep her at full HP. In terms of the atk, there's the option of giving her Death Blow 3 (but that means giving up distant defense, making her weak on the enemy phase). With Death Blow 3, at full HP, even with the atk. bane, she'll sit at a huge 55 atk (especially with the speed boon, she'll have a higher chance at doubling), at the risk of her defenses. C skill can be anything, really, depending on the needs of your team.
For support skill, I was thinking a movement based skill. You could also give her reciprocal aid (though this would only work out if you run multiple tanks).
For a special, I'd probably end up running Noontime (again for the heals) or something like Draconic Aura. Her current special is fine, but especially in arena, it's very difficult to trigger as battles usually last less than 5 turns.

Personally I have a -atk +def Tharja, and I gave her Life and Death 3, and she's been great with that. And ardent sacrifice, desperation, as well as glimmer for the potential to 1-shot a Hector regardless of IV's with no counter-attack. I feel like the Red Blade tome is pretty consistent and manipulable for arena settings when you need the bonus damage, whereas Ragnarok is gonna be very dependent on staying at max HP. Tharja's good at either max or less than 75%, which is easily achievable with L&D 3 equipped. Celica's not a bad unit, and those IV's do seem pretty usable. -atk really isn't great though. Doubling wouldn't be much of an issue, but picking up the kills will be. You could do a similar all out offensive skill set and that would be ok, but not quite as good as Tharja for that role. Unless you can find a different role for her, I'd say Tharja's consistent great offense makes her more viable for arena offense. You could consider giving her distant defense to Xander for arena defense (and maybe offense too).