I just went back to the earliest save I had of Baa the stealth archer at level 3 from 2008. I used her just as I found her and didn’t try to spice up her equipment. She did recruit two companions that weren’t available in 2008. Baa borrowed 200 Daedric arrows from them to use. Stealth didn’t matter much to Baa, because after the first shot, it was all down hill from there anyway. I was just playing around seeing if I could do it. I guess I could have found a better bow than the Rusty Iron one she was using, or even borrowed a Daedric Bow from a companion. Or even making up some kind of poison, since all my characters become master Alchemist and rely on poisons for their arrows. But I didn’t, and I had fun playing around with it. I made no saves during the adventure, so all of that info has vanished and Baa is back to her normal self in 2012.

I don't really understand the fascination with that sword, and I don't generally play the kind of character who would attack an innocent person to get something like that. If you're doing this before level 20 (without Clavicus Vile assigning the quest), there's no legitimate way to initiate the fight without being the aggressor. And if you're doing it after level 20, I can't imagine that you need the sword anyway.

I greatly preferred the Morrowind version of this, where the Orc warrior with the sword expresses the wish to die in honorable combat. It's a much more morally acceptable approach for the "good" character.

I agree with glargg there. The Orc wanted to be killed in a fair fight, Oblivion-Umbra just stood there without posing an immediate threat or having a death-wish.

I agree. That is why my characters always disarm her to free her from the foul sword's control, then ensure she safely gets home to Pells Gate to resume her life as Lenwin. The sword then ends up in a lava pool somewhere. Screw Vile.

The sword's high base damage makes it a good backstabbler, but it is of limited use until you can repair and recharge magical items. By that point, better swords are available. A much better choice for a low lever sword user is Honorblade which also wieghs 0, has great damage and kills ghosts. Unlike Umbra however, it can be repaired by a novice and has no charges to replenish. Another consideration of using an 'uber sword' is that it slows leveling of the blade skill due to less hits being required to kill stuff. This is a good or bad thing depending on how fast you want blade to level.