Roux's quirk is uinque, never before seen. Its abilities grant incredible defensive capabilities for her and those around her. Her own body is many times more durable than normal, her muscles and bones many times denser than normal because of an abnormally high carbon content within them. On top of this her skin is as smooth and flawless as marble, and when she activates her quirk it becomes just as hard. Because of the incredible density of her musculature she is stronger than she appears, easily carrying a hundred pounds under her arm and increasing it to roughly 800 when she activates her quirk. The one down side to the Sentinel quirk is that while heat and flames have no effect on them, intense cold, lower than 32F, causes the user's body to become stiff and sluggish, and if exposed long enough can even cause their hardened skin to become brittle and crack when they move. Roux herself has her own personal downfall, being that because of the higher than average density of her bones musculature she lacks the ability to swim. She sinks right to the bottom, and if she cannot make it into water shallow enough to stick her head above within the two minutes she can hold her breath, it can be fatal.