Fairly basic help...Bloodlust item?

Basicly I want to make an artifact item that casts Bloodlust on the bearer when used...how would I do this so it automaticly picks him as the target instead of just making an 'item that casts bloodlust'?

Also, what sort of contrived artifact history could you suggest for such an item? especially one found in a frozen tomb.

For the first question, base the item ability off 'Frenzy', a Neutral unit ability used by summoned Quillboars. It acts just like blood lust, except it targets the caster.

For a somewhat 'generic' artifact, this description might do:
"Dragon's Tooth Necklace
Bearing a single tooth of an ancient dragon, this leather cord has
almost unreadable arcane writing running along the whole of its length.
It apparently keeps the leather safe, for even after untold years spent
in a frozen tomb it still looks and feels brand new. When activated,
it will channel the power and fury of an angry dragon into its wearer,
granting an increase in both attack and movement speed for a short
amount of time."

For something more 'unique', it's hard to write and history up while knowing nothing about the setting of your map. If barbarians in some form are or were present in the general area of the tomb, shamanistic origins related to them would probably work well.

make an or 2 abilitie's wich give the bloodlust stat enhancer's (+mov/attackrate) and make the abilitie's give the bloodlust effect on both hands, trigger increase their size to 125%