Benesa first came to the notice of Orcus in a far away plane at a place called Rappan Athuk. Captured and brought before the Demon Prince of Undeath by one of his baloric followers named Ter-soth after she and her companions make themselves a minor nuisance in his attempts to build the first of what would later be three temples at the large world spanning dungeon.
The party had been fleeing a group of illithids lead by a mighty elder brain when she lost track of her friends in the panic and hid in a nearby crevasse. Unfortunately it was to close to the new First Temple of Orcus and she was discovered by Ter-soth Given a choice between him killing her and the chance to talk to his boss she chose the latter, not realizing it was the mighty Orcus himself.
Her and her friends had been raiding the temple for supplies and general adventuring hubris for some time – not realizing that Orcus himself was personally overseeing the building of the three temples and was, in fact, located in the very depths of Rappan Athuk.
He explained his displeasure at even having to speak to such a lowly mortal and without a moment’s hesitation Benesa quickly drew a staff she had recently acquired and broke it on the steps before Orcus – mid sentence.
The damage incinerated her and forced the demon prince to recoil, singing his fur.
Brought back from death by her friends, there began a guerrilla war in the dark of the mighty dungeon from the bottom of the depths to the vaults of the planes spanning all worlds. Orcus priests turned up everywhere allied with anyone. Assassination attempts were a constant hazard and became second nature.
Two more times she faced Orcus escaping each conflict. His anger remained white hot from not only at his plans under Rappan Athuk being brought to a halt but at the affront at having his nose tweaked by a little slip of a drow.
Eventually she became a seer and hides in a plane of her making. An artifact cauldron gives her glimpses of the future. She uses this information to remain always one step ahead of the demon prince. That, and duplicates of herself scattered across the multiverse to confound and confuse his followers.
She continues to throw monkey swarms in his plans aiding and encouraging adventures working against him wherever they may be – knowing full well, one day, the prince will come for her personally.