Overview
OBR's new Skill 2, Frost Edge Rehoning, is her main selling point. While her Skill 1 is in effect, she will target the enemy with the highest Damage stat and apply a stack of Frost Edge with each shot. Once she has shot at a target 3 times or the skill duration ends, each stack will be consumed and deal guaranteed Damage that ignores Armor and HP Shields.
The main benefit here is actually the targeting, which lets OBR serve as a highest Damage enemy killer. Getting rid of whatever enemies can deal the most damage first is beneficial for obvious reasons, while the stacks that deal guaranteed damage help to offset her original poor DPS. Do note that enemy support units such as Murats and Quill of Patmos have a very high Damage stat, usually making them the first targets to be killed, as desired.
Overall a simple and straightforward but strong upgrade. OBR will be a worthwhile addition to your roster with a useful niche. MOD II is necessary to allow her to fulfill said niche, with MOD III being a nice optional upgrade.