Gáe Bolg, a cursed spear crafted by Scáthach from the remains of the Phantasmal sea monster Curruid's skull. Scáthach made several versions of this spear with the intention of one of her students being able to kill her. The Gáe Bolg is descended from Gungnir, which is Odin's spear in Norse mythology.
The spear has two unique attacks that you can use. The first is Gáe Bolg: Barbed Spear That Pierces With Death. This attack is focused on a single opponent, and it always strikes the opponent's heart, ensuring a fatal blow and spreading tiny thorns within the bodies of those pierced by the spear. Once the name of the spear is called, the spear reverses the causality of nature, ensuring that no matter how much the opponent struggles, the spear is always fated to pierce the heart of the one whom the wielder strikes. In other words, instead of the cause being the lance being thrust, it is replaced by the effect of the lance piercing the heart, even turning at angles that would otherwise be impossible to pierce the heart. There is no hope of evading this attack unless the target has a way of changing their fate themselves.
Wounds that come from the spear cannot be healed unless the effect of healing it is greater than the curse that is on Gáe Bolg, as long as the spear exists.
The second technique is Gáe Bolg: Soaring Spear That Strikes with Death. By tossing the spear and unlocking the true potential of the spear's curse, the wielder produces thousands of barbs that all strike at once, effectively carpet-bombing an area. This attack is more effective against multiple opponents, as it cannot be dodged or blocked under normal circumstances.