*cough* You can try this approach without resetting the game by giving the dagger to another character while receiving your promotion. However you will only get the Grue Morde quest once.

But *cough* remember, fair Willow, *cough* that this only *cough* works in the *cough* unpatched game.

The patched game cleans up this little *ahem* loophole.

Whenever you reset the game, all quest items disappear (with a couple of exceptions), and all critters you ought to kill come back to life. Mon the Sculz, Juba Thobers, Tevik Teporn, Grue Morde... they're all back...

The ways to two (or more) assassins involve resetting after one becomes an assassin or using the *cough* quick hand-off trick that Willow mentioned above.

The bizarre bug.
1. Eddie seems to get quest reward for the Band of Boars quest repeatedly. Several other quests suffer from this bug (for example Jathil, Leprechaun, or Grue Morde). I do not know the complete list of all quests which are buggy this way. Does the Band of Boars quest belong to the list? Does the bug reveal only sometimes? I don't know.
2. The Iron Lung trait is a guild level 5 Thieves Guild trait. It is available to barbarians and bards. It is not available to assassins. It does not seem to be available to non thief roles.
3. The Backstab trait is a guild level 6 (or 5?) Thieves Guild trait. It seems to be available to all roles.
Summary: The bug upgraded Eddie's bard (see Eddie's list above) to guild level 5 or 6 and allowed the bard to gain the traits. The bard would be able to get both traits later in the game. All other characters will be able to gain Backstab trait later.

Note about the Iron Lung trait.
The Ring of Neptune contains the trait as well. You will find the ring of Neptune in Collasium (Beware! The ring looks like an ordinary Ring of Gedda! Do not throw it away [img]graemlins/hehe.gif[/img] ). The ring can be used by any role.
Therefore, all your characters can get the Iron Lung trait. All characters can invoke the ring and recycle the ring through a shop. The ring survives reset adventures so that it can be inherited from one game run to another. In the other words, all your characters can get the Iron Lung trait at the very beginning of the game :D

So the assassin's dagger is a quest item like the other special role quest items (the four tomes and the lich's heart)?

Yeppers, it is a quest item. Unless Radek corrects me and says it's really a special sub-class of quest item, since you're not actually quested to get it. Of course, you are quested to do something with it or for it, but that doesn't work for the four tomes...

I need a drink. :D