This would have received a higher rating, if it just wasn't so gosh darn hard to find and buy. I've haven't seen one in months, but if I did, they would go for more than Grapes of Wrath.
The reason this is so expensive is because it is not only good, but it can only be won by redeeming a TCG, thus, being very rare.
One could say this is a Scuzzys Comb, combined with a Ramtors Spellbook, with additional physical, not to mention the priceless defense. But instead, let's look it as 15 great icons that get through burrow, and an additional 6-10 physical, for a total of 21-25 icons.
Sword of White Lies is a similar weapon. Both deal mass light, and what Skarls Sword lacks in light in comparison, almost makes up for with extra physical. You would also be trading out 5 air for 5 dark, whether or not that makes a difference to you. I consider this sword better however, due to the fact that this blocks all light.
So don't forget about its defense. To block all light is pretty epic. This turns the previously mentioned Sword of White Lies into just 5 physical, and 5 air, Sword of Thigl to even less dust, and lets this sword win head to head against Seasonal Attack Pea. It also allows you to consider shields different than Hubrid Nox Memorial Shield and Dr. Sloths Personal Body Armour in case you wanted to go with a sword and shield combo.
In conclusion, I consider this sword power wise, just below Sword of White Lies and Ghostkersword, but due to its unique light blocking capabilities, I would rank this sword higher than Grapes of Wrath.
Counters: Surprisingly, this weapons upgrade seem to be the best counter. Or simply try to out offense it with the attack pea or Sword of White Lies, Ghostkersword or Grapes of Wrath. Also however, I'm excited about this, Dr. Sloths Personal Body Armour pretty much lowers this to dust. Seeing as most league battles are fought where defense is higher than offense, this armour does great! Let's just hope Dr. Sloth doesn't attack Meridell... oh wait, that would be epic!
Upgrades: With these icons? Hmm, this sword is truly unique, and the best at what it does. Power wise, one could look at Sword of White Lies. For all dark, a reflection in light, and some great healing, you could go for the more expensive
Wand of the Dark Faerie or Illusens Staff.
Alternatives: None. This sword is unique at this level.
Downgrades: Downgrades with this dual duty like deal include the following (from strong to weak): Jhudoras Bewitched Ring, Dark Faerie Collar, Air Faerie Crown, Dusty Magic Broom, Jhudoras Cursed Sword, and lastly Sword of the Dead. Boy, Jhudora sure likes to counter light.