Don't be so sure you want one..
1. It eats away your health 1hp / sec. This means that between fights, you'll have to carry another blade or you'll lose your natural regeneration.
2. Every
successful hit gives you 3hp, but in order to negate the 1hp loss / sec, you have to hit REAL fast, which means this blade needs high swordmanship and its best in tight situations where you face multiple foes.
Last point - it does slashing, not elemental damage. Personally, I prefer elemental over physical damage.
Just my 2 cents..