OMG!I cant belive you dont not understand it!Geostigma is a virus that is JENOVA,JENOVA merged with the lifestream,then when new children where born she became Geostigma Kadaj took control of the children because he wanted a reuinion(when jenova cells go to the sme place and merge)so the children with the Geostigma(JENOVA)went to the sme place as kadaj n crew in midgar.and i know what ure thinkin ''eh but cloud had geostigma''indeed he did but he also was there in the forest with the children then in midgar.
Not got a pic of it but was the rain holy or areis?(it cured geostigma)