Hoshidan Micaiah +hp -res

Even with a res bane, she can still completely wreck cavaliers and armors. She has 31 base resistance, and most of the foes that she's effective against don't have much resistance compared to her unless built for it (which is hardly ever).

She hasn't lost any atk, and as I pointed out in another question, she crushes her most important matchups even with an atk bane (Zelgius, any green armour except maybe Sheena, Ares, Swordhart).

I'd be more concerned about the res bane if you're trying to use a QR iceberg strategy against red and green mages. The extra HP will help compensate just a little bit, but the IV is very slightly bad for this purpose.

Ploys are an interesting question. She can still hit Zelgius, Hector, etc. but she doesn't need to ploy them for res. There are lots of mages she won't be able to ploy, especially the ones she would most need to ploy, which means I don't think res ploy is good on her anymore. If you still want to spd ploy to hit Karla and non-fury Ishtar so your teammates her deal with them, it could still work. Pretty much all the hyper-speedsters will get hit by 31 res except +10 fury Nino.