Let's complete some of the missing pieces from Walkure Romanze. Poor Mio got the short end of the stick: while a decent support character on the common, her actual route in the VN was quite subpar.
Trained on NAI. Recommended weight of 0.7.
Trigger for her uniform and other outfits: miowal
Trigger for her armor version: mioarm
School Uniform
hairclip, school uniform, epaulettes, aiguillette, pleated skirt, kneehighs, shoes, brown footwear
Armor
helmet, plume, shoulder armor, breastplate, gauntlets, pleated skirt, armored boots
Just replace "helmet, plume" with "hairclip" if you want her armored version with the helmet off.