User blog comment:Gundam Legilis/Volume 1 Weapons In Depth - Ember Celica/@comment-10390252-20140616140518

Given what we now know about Mercury's weapon, I suspect that Ember Celica is part of a family of weapons that I call 'Augmented Melee', that are intended to enhance what would otherwise be pure unarmed combat skills. I suspect that Miltia's claws and Melanie's knife-stilettos also fit into that category and so, possibly, does the weapon used by one of Velvet's team-mates that has blades on wrist-bracers.

Based on Yang's fight with Melanie, I'm pretty sure that the upper surface of Ember Celica is armoured. I think Yang has developed (or uses an existing martial art) where she uses her wrists and forearms to block.

However, she's a brawler, trained and optimised for point-blank- or short-range fighting, so she needs a ranged fighting specialist like Weiss to defend her from long-range threats.