Oooh ooh is it the sleeping man near junon? If not...does it get you a materia? "In favour of the green" does that mean a materia, or just benefiting the world? Fort Condor, maybe? Heavens grant might also be a materia, but i think it's more summon materia. So, either a summon materia which helps the environment, or a green materia, which doesn't really. As to the last verse...Comet materia? It's found in City of the Ancients, in a room you don't have to visit, but i think it gets blocked off after Aeris dies...maybe i'm wrong, idk.