Fragarach

In Irish mythology, Fragarach (or Freagarthach), known as "The Whisperer", "The Answerer", or "The Retaliator", was the sword of Nuada, the first high king.

[1] Nuada lost his arm in the first battle of Mag Tuired and, being mutilated, was no longer suitable to be high king.

So, for the second battle of Mag Tuired, Nuada chose Lugh as provisional king.

Using his spear and a sling given to him by Manannán mac Lir, Lugh defeated the Formorians and their king Balor.

The sword was also said to place the wind at the user's command and could cut through any shield or wall, and that it inflicted piercing wounds from which no man could recover.