Overview

UTS-15's niche is giving all Dolls in a square surrounding her (if she's on pos5, she hits all other nodes) 10 Armor. For most content this is entirely pointless, but for certain enemies such as Coeus this can be very useful, and as it is a flat Armor buff, it can also be useful while debuffed by Parachute's debuff (the +10 is after the debuff's reduction).

The in game description for how her Accuracy buff works is entirely incorrect, it's actually affecting the Dolls on her Tiles, not the same area as her Armor buff (see her Tilebuff). Utilizing this requires putting her in the frontmost column, which means you need her to tank. This is not a good idea, as she does not have the Armor to be there having among the absolute lowest Armor in the game (Nova has a permanent self-buff to Armor and Defender is a DPS SG).

As such she is almost entirely just used for her niche of Armor-buffing the echelon and not used if this is not needed.

Also take note that Damage Reduction is calculated after Armor, so the Active portion of her Skill is largely useless.