Kupann - The Liquid Demon Blade

The legends tell of a great Tuskarr spirit singer that defeated the demon Ruthalax, but the sprit-singer was so powerful that he denied the demon its escape back to the Infernal realm, instead sealing and binding it to a crystaline flask.
Wielding the flask one can attempt to dominate Ruthalax and gain the ability to use it as a one-handed blade. The blade is able to cut through otherwise impervious holy items or holy materials. The more Ruthalax respect or fear you the more of his power the blade possess.