From ErfWiki

Proposed Canon

Parson received a sword in three consecutive Stupid Meals starting on his third day in Gobwin Knob. He received the hilt first^Erf-b1-p077a, the forte (blade near the hilt) second^Erf-b1-p086, and the foible (blade away from the hilt) last^Erf-b1-p106.

The sword is described as conveying Leadership, Combat, and Ruthlessness.^Erf-b1-p106 However, Parson had a "leadership bonus" before acquiring any part of the sword^Erf-b1-p040a.

Parson appears to destroy his sword by tossing it into a pool of molten lava at the conclusion of book 1.

Speculation

It is not known how real or magical the powers of the weapon are. It certainly acts as a killing weapon^Erf-b1-p133, but it gives no overt signs of exceptional magical auras or ability. Parson's eyes glow red^Erf-b1-p106 upon first receiving the completed blade, but what that actually means is left to the reader, one interpretation being that at that moment, the Ruthlessness was conveyed to him. Since Parson's leadership bonus existed before he got the sword, it is reasonable to believe that his unit leadership ability is not reliant on the sword's magic, but is possibly amplified by it.

Parson appears to refer to his sword as being named "ruthlesness". ^Erf-b1-p148 He at least appears to identify his ruthless actions with the completion of his sword.

As the sword melts, there is what looks like a stream of energy leaving it.