During Atlas's Quest in Pandora's Temple, you will encounter a series of stone walls which you can climb. Several armored legionnaires will try to knock you off of the wall. Kill all of them and climb to the top of the tallest ledge. A glitch Harpy will begin to screech, and blood (experience) will start to shoot at you. It will last for as long as you stay in the area. This is an easy way to raise your weapons and magic spells to the maximum. If you look close enough by one of the treasure chests, you will see what looks like a holographic Harpy flying in one spot.