For a multi-type team (other than light) when choosing reinforcement units it is advised to get Gemini II & Mina due to her leader skill: Divine Gale which Nullifies all status ailments (prevents you from getting cursed by Shadow Oboro).
For a COMPLETE light team, it is best to get reinforcement units such as Blade Queen Sefia, God Knight Will and God Atro to further boost your light attacks to 100% (50% from leader + 50% from reinforcement).
Likewise, if you have Legionary Melchio or Centurion Melchio, bring him along for his BB.
If using a full light team, bring Light Seals and Ores for 3 turns increase in attack and defense.
Recommended Spheres to use: Angelic Foil, Sacred Jewel, Medulla Gem, Muramasa. (Use only if your attack is very high).
Gradual healers are recommended, using Cures to top up low health units. This is due to him tending to target different units every attack. Offense is not the best defense here