Makeup artist here. For sealing makeup, it really depends on what KIND of makeup. If you're just doing the normal cosplay makeup routine, then find a transparent powder and seal with that between layers. Revlon PhotoReady is one of my favorites. If you're scared it wont' work because of heat, movement, etc., then some Ben Nye on top works. If you're using bodypaint, Same thing, but don't be afraid to be SUPER HEAVY in your use of either. Hairspray works in a pinch, but I find it too irritating.