Stormbringer

)   Stormbringer
Base item	runesword
Damage vs. small	2d4 +1d2+1d8
Damage vs. large	1d6+1 +1d2+1d8
To-hit bonus	+1d5
Bonus versus	not drain resistant
Weapon skill	broadsword
Size	one-handed
Affiliation	chaotic intelligent
When carried	(none)
When wielded	bloodthirsty drain resistance
When invoked	(none)
Base price	8000 zm
Weight	40
Material	iron

Stormbringer is a chaotic artifact, and the only runesword in the game. It is considered a broadsword for skill purposes. It drains life from monsters it attacks. It is bloodthirsty, attacking peaceful monsters and pets without confirmation if you walk towards them.

The damage and to-hit bonuses are applied only against creatures not resistant to level drain.

Encyclopedia description

There were sounds in the distance, incongruent with the
sounds of even this nameless, timeless sea: thin sounds,
agonized and terrible, for all that they remained remote -
yet the ship followed them, as if drawn by them; they grew
louder - pain and despair were there, but terror was
predominant.
Elric had heard such sounds echoing from his cousin Yyrkoon's
sardonically named 'Pleasure Chambers' in the days before he
had fled the responsibilities of ruling all that remained of
the old Melnibonean Empire.  These were the voices of men
whose very souls were under siege; men to whom death meant
not mere extinction, but a continuation of existence, forever
in thrall to some cruel and supernatural master.  He had
heard men cry so when his salvation and his nemesis, his
great black battle-blade Stormbringer, drank their souls.
[ The Lands Beyond the World, by Michael Moorcock ]