Tried this on Nazeem first and I liked it.
1.Cast soul-trap on Dark Brotherhood Contract.
2.See with which weapon he attacks you and remember.
3.Kill him.
4.Enchant his weapon with his soul, but judge the amount of charges with the difficulty(low difficulty-high ammount of charges), and name the weapon with his name.
5.Place the weapon in a rack or the complete set in a chest.
6.Feel evil.