There is currently an Item in game that deals Light Damage, other than the new shortsword. Radiant Arc in Rainbow in the Dark deals light damage and last time I checked, it bypassed all DR in the quest including the Earth Ele's DR/-. I also believe that Rad II transforms the damage dealt on a crit to light damage, not sure of that though. The new Short Sword has some serious Damage potential, as it wouldn't be effected by DRs of any type, and *should* be modified by Stacks of the FvS aura thingy. However, anything with Light Resist would be seriously affect it's damage output (LoB mainly)