Mournlode Shortsword, Mournlode Longsword, Mournlode Greataxe, Mournlode Light Mace, Mournlode Warhammer, Mournlode Maul
lvl 8:
Incandescence Effect: This weapon glows with the light of Irian. This weapon deals an extra 1d6 points of light damage on successful hit.
lvl 12(and onwards):
Brilliance Effect: This weapon glows with the light of Irian. This weapon deals an extra 1 to 6 points of light damage on a successful hit. In addition, critical hits deal an additional 1 to 10 light damage for weapons with a x2 critical multiplier, 2 to 20 for a x3 critical multiplier, and 3 to 30 for a x4 multiplier.
lvl 20:
Radiant Blast Effect: This weapon has a 1% chance to proc 240-525 light damage (probably 15d20+225). Average: 380 (experimental avg was 380.2), which is 3.8 damage per hit.
Deals +100% damage to all undead (probably 480-1,050, 30d20+450), which is 765 average, or 7.65 per hit (experimental avg was 757.85). Creatures vulnerable to light take extra damage.
Note: All Undead take the extra +100%, plus potentially additional damage based on their light vulnerability percentage (if any). EG: Vampires are undead, thus take 200% damage. But they also generally have 50% light vulnerability, thus they take 300% damage (2.0 x 1.5 = 3.0): (720-1,575), which is 1,140 average, or 11.4 per hit.
Admittedly, you have to run torches, curse at kobolds, and all that fun..