The Killer Rune contains the power of compressed hits, resulting in very critical direct damage to the enemy. It aims for a series of harmful strikes, especially if the wielder is used to critical hits already. In a manner of speaking, a true killer will be born, once the rune is attached and the preconditions like high attack and skill stats are set.
The Killer Rune is very popular among strong fighters, in particular those who lack on good magic skills to benefit from free rune slots otherwise. Georg Prime is a memorable operator of both his sword and the Killer Rune attached to his right hand. These crystal are a common item, sold in various shops around the world and carried by different enemies as well, yet very useable in battle. It raises the inital probability of performing critical hits by 50%, and used during the Sun Run War it even adds a little chance of an instant kill. That is, if the enemy survives the brutal hits at all. In the Falena Queendom this rune is unusually expensive. - Celes