want to get rid of it? go to the area just before the former al bhed home and just south of the valley caked in a sandstorm is a stone with a cactuar on it. examine this to get rid of it (u'l also get a clue as to where the next sphere is). if u get all the spheres you will get a prize item (depending on how u did with the cactuar minigame) and a mercury sigil from the valley. the sigil is used to power up rikku's CW.