D&D rules are hard to keep up with lately Nanobyte. Going back to it's origin say you picked up a low level Balrog sword. It was an Evil +1 flamming sword. Magical swords always got a dice roll to see how powerful it really was. So if a low level character picked it up often times they couldn't put it down without a dispell majic.
Then sometimes the sword wouldn't pocess the person until battle. Like a berserk spell gone bad on the party.
These are most likely outdated rules by now but that was part of the original 3 book style. Very exciting and from hence it grew.
So I would say yes to the evil draw on the sword. It should be dispelled off if you have to. I'll go away now

D. W.