Shimare

Shimare is a character in the lore of Dota 2.

Biography
Mayhaps Shimare created the or at least was involved in its creation since their possessive name is invoked when others cast this spell. Hence, Shimare should be a mage.

But it isn't just Shimare who is invoked when others cast the spell, as Endoleon is also invoked when others cast it. It's unknown if these two mages are related to each other.

Since the young Invoker (who existed during the ancient times when spell-casting was once at its most potent form because it was still primarily a mnemonic art) learned the E.M.P. spell alongside his nine other invocations, Shimare must have existed during this golden age of magic as well and hence this obscure mage must've been an ancient one too.

Inheritance
In his youth, the learned Shimare's  alongside the nine other spells he currently wields, using three Wex orbs to invoke this spell for casting.

Immortality
Having existed during the old ages when magic was primarily mnemonic, Shimare must've been quasi-immortal like the other ancient mages whom Invoker sourced his spells from.

That is, assuming that Shimare is still alive today like Gallaron...

Magics
Like the Invoker, Shimare must have had the power to spells with the energies of. Otherwise, Shimare would not be able to cast or even have this spell (which stands for Endoleon's Malevolent Perturbation  or Extractive Mana Pulse, a.k.a. Shimare's Extractive Pulse or Wex magnelectros ) which is invoked via Wex Trionis.

As the spell's names suggest, this magic builds up a charge of electromagnetic energy that, once detonated, siphons the mana of those caught in the pulse to the caster.