Abyme from Fire Emblem Engage, with support for both her Armor class and her Berserker class.

One of the only enemy units I can think of who actually, noticeably Class Changes. Of course, because she's only a minor enemy? Getting both outfits to work was... an endeavor, to put it lightly---which is why there's now a V2 version.

V1 Trigger Words can be found on the V1 model.

Trigger Words (General): AbymeFEE, blonde hair, short hair, forehead, brown eyes,

Trigger Words (Armor Knight): AbymeArmor, grey armor, neck guard, breastplate, brown shoulder armor, grey shoulder armor, gauntlets, armored gloves, two-tone gloves, grey gloves, green gloves, black shirt, long sleeves, grey armored corset, brown hip armor, grey hip armor, black pants, green pelvic curtain, leg armor, armored boots,

Trigger Words (Berserker): AbymeBerserker, fur capelet, white fur, high collar, o-ring top, green shirt, dark blue trim, white shoulder pads, brown bodystocking, detached sleeves, brown sleeves, fur trim, arm guards, green gloves, fingerless gloves, green pelvic curtain, green showgirl skirt, long skirt, knee guards, shin guards, brown shoes, open-toe shoes,