he was an immortal warrior who 'd long ago stolen and opened pandora 's box to `` teach those ass**le gods a lesson '' for daring to pick a `` mere woman '' to guard such a `` dumb relic , '' and because of his rampant senselessness , he and the friends who 'd helped him-the infamous and deliciously frightening for everyone but a harpy lords of the underworld-had been cursed , forever forced to carry the demons they 'd set free inside themselves .