Ok, first I must confess my bias: I am very cautious of slaying weapons and disapprove of instant killing items. This item here would greatly unbalance my current fantasy campaign. (Despite this fact, I sometimes create such items myself).
Now the actual critique:
As usual Scrasamax has delivered a very good piece of work. As a matter of fact I consider this the penultimate proof that a seemingly munchkin idea can be rendered usable, even great, if created by someone skillful enough.
Nice background and nice item, but too powerful.
An idea could be to let the dark god want something in return for his gift... (for game-balance)
We are all aware that it is a good item Sentinel*. Scras is even one of my favourite GMs here.
But we must remember that there are many GMs out there that simply adopt items like these from a site. They should know what would happen to their campaign if they freely gave it away. Killing dragons would be simpler than killing D&D kobolds!
So yes a good item, but one to be inserted with extreme caution.
~Ancient Gamer Go to Comment
You forget lesser gods of evil. ;) They want to have some fun, too. Too bad the main baddie spoils it regularly. (May be another reason why the world was "helped".)
A truly evil god would not spare the bad guys of his sense of humour, right?
While plagues, madness and mutations can be expected, the evil supreme being would likely research more ways to Evil... creating places seemingly peaceful, with much suffering underneath, and many others...