R9 Naga Shortbow Weird Inherent Mod

Johny bravo

Wilds Pathfinder

Join Date: Aug 2006

[SoS]

N/

08 Nov 2010 at 10:50 - 1
So yesterday while doing some speed clears I ran into this

Naga Shortbow of Dragonslaying
15% -1 energy (inherent)
20% against Dragons

I know that inherent mod is an odd one but I usually have seen it on swords. Is there any kind of value for it on a this bow or should I just merch it?