Complex sentence: Shirogane attempted to fight the Org until his Power Animals return to him and allow Shirogane to transform into GaoSilver and killed the Org with his "Evil-Crushing Seijuu Orbs" attack.
Split into simpler sentences: Shirogane attempted to fight the Org until his Power Animals returned to him and allow Shirogane to transform into GaoSilver. This Org was then killed with his "Evil-Crushing Seijuu Orbs" attack.