I know we have the airship idea (which Helios will be using the MAV to test it on since lol autoshift so if things explode...>__>;) But I've always had Helios talk to Leon about putting up barriers on buildings and stuff. Maybe even combining his gem system with his own barriers somehow. But other than that I am game for anything and everything~

He's also taught numerous people filial magic so far...so I'm sure he can lend a hand with that!