What A slot skill for +Spd -Atk S! Sharena?

I was at a 5.75% pity rate, rolling on the spring banner since the beginning of March, and I did my daily yolo summon this morning to get a Bunny Sharena! You don't know how glad I am to stop rolling on this banner, all I wanted was one bunny unit. Anyway, she's +Spd -Atk, and I definitely want to keep Munnin's Egg on her, so what do you guys think I should put for her A slot? A full build would be even more appreciated! Thanks :)