Blade of Woe in Oblivion: No Cheat, Only the Dark Brotherhood Quest

How to Obtain It Legitimately

1. Join the Dark Brotherhood (triggered by killing an innocent NPC and sleeping).
2. Progress through the questline until "The Cursed Crew" (part of the Purification).
3. Complete the quest — the Blade of Woe is awarded by Lucien Lachance.

The blade is a powerful one-handed dagger with a 12-point Absorb Health enchantment. Using console commands (player.additem 0002260D 1) on PC works, but on consoles you must play the questline.

Tip: If stuck, check UESP or the Official Oblivion Wiki for a walkthrough of "The Cursed Crew."