Supersteel
From Jenny Everywhere Wiki
In one universe, supersteel was an extremely hard substance common on Mars. When she realised that her superpowered niece Jane intended to run away from home, Kanza attempted to stop her by locking her up in a windowless supersteel room, not realising that Jane's powers included enough strength to tear through the wall bare-handed. (PROSE: Magician From Mars…)
