A benefit that doubles the effective mass of any living creature Katia strikes with her moving body.
Avalanche is the marquee benefit of the Enchanted Wrestling Belt of the Great Gorgo that Katia Grim wins on The Iron Tangle. Straightforward and brutal: if she hits a living creature with her body while her whole body is moving, the force is applied as though she had twice her mass. It does not translate to weapons — only body-to-body impacts — making it a natural amplifier for her plow-runs and her Rush charge. (The item wryly warns her to take the belt off before getting intimate.)
A passive combat benefit, no visible manifestation beyond the added force of Katia's body-slams.
A mass-doubling momentum benefit that supercharges Katia's body-impact attacks.
Also appears in books you've already read — spoiler-safe to their endings: