Board Thread:False Info and Speculative Discussion/@comment-5705606-20150630141745/@comment-11533671-20150701031536

Obsidian is both hard and brittle. Depending on the density, a human can break it by hitting it since it is essentially glass formed by lava.

As for flipping the Oni; judo, wrestling and other fighting arts prove that isn't impossible if one knows how to apply counterbalancing.

Kitsune may or may not have greater strength than humans but nothing so far proves it, imo.