Wind

Valinhall_Power_Template effect = Assists Dragon's Fang in cutting invulnerable materials

The power of wind is rarely used in the books and it's limitations are up for debate. However, on a most basic level, wind can be called on a travelers Dragon Fang, appearing to heat and sharpen the blade. This ultimately has the effect of allowing the Dragons Fang to cut materials that would normally be invulnerable, notably, Tartarus Steel. The limits on what it can and cannot cut are unknown, as is it's location and challenge within the house.