moonbow or glimmer for lewyn?

Depends on how good the res of your opponent. If you're going to use a 2CD special I say go with glimmer because special spiral implies that you're preparing to fail to double for whatever reason. If you're going to use a 3CD special, your choice of luna or draconic aura. Luna will cut hard into anyone with high res, but they need like 36+ res for you to justify it, more still if atk wave is active. Draconic aura just gives you a consistent extra 15-17 damage.