Halloween Mia

So I gave my Mia Pain+, Gravity+ will still likely be my main. But if Mia w/Pain+ is able to cheese any of the abyssal maps then it will be worth it in my eyes! Although I'm wondering what other A-slot if any I should give her? Also should I give up the extra Ethlyn to give her Live to Serve 3? Since I didn't bother upgrading the seal and have like 10 coins, as I used them up for the Brazen and Darting Stance seals.