1. Hermes Sandals. Very little of what Exdeath and NeoExdeath throw at you is actually significantly reflectable (The main magic-using one is usually instantkilled via Magic lamp anyway)
2. Are you on the SNES or GBA version? In the SNES version Rapid Fire is weaker because of the 'false targets' on NeoExdeath, but those aren't on the GBA version so RF is probably better. Still, GilToss is guaranteed damage to all targets. Make what you will of all this.