Well, I ended up with nee-san pirate lady Drake after wishing hard for any of the three casters... she any good?
Well she's at least better than medb(who I pulled :( ). Her main use comes from farming if you pair her up with a waver and mage mystic code, she's capable of firing her np 2 times in a row if you have her 3rd skill maxed, beyond that she can buff everyones np damage so pretty useful. or you could use her in a crit buster team if you have a star generator.
As someone who has a lvel 100 10/10/10 drake, I can confirm she is very good.
When it comes to boss battles, she can suffice, but is not the best. In literally any other encounter though, she's godlike. Even if it's all assassins. With only her self buff, she can deal about 50k to all enemies post-interlude. Pair her up with two wavers and anniversary blonde/nightingale, and you're looking closer to 80k. Her NP generates crit stars, which she can then use with her second skill and her two arts cards to practically get back up to 100% the next turn.
TL;DR: Her use in high difficulty quests vs non-casters is questionable, but in general use she's probably what I consider to be the best and most consistent servant currently in NA
