+SPD -atk Celica or +res -hp?

As much as it hurts to say, IMO you should go for +Spd -Atk. More Speed on Celica is amazing since you can quad slower units with Double Lion and even trigger a special. Celica doesn't need resistance because she shouldn't be dealing with ranged threats, and her HP is already in the lower end for melee units.

With +spd your quading neutral speed ayra,karla, mia and anyone else with deathblow 4......enough said lol.

DB4 costs as much as DC so I'm expecting to see it a lot in the Arena.