Knowing that my Dragon Shield will reduce the attack damage to 5, any hits from the Druid on Round 2 will apply to the Efreet and since the Nightmare has regeneration any hits from the Pixie.
The Efreet will use Fire Illusion in Round 1 (targeting the enemy with the highest hit point total as per the rules for this combat).
The Djinn will use Wind Blast in Round 1, targeting as above.
The Djinn will use Wind Gusts in Round 2 (targeting the Druid).
If any enemy has 10 or fewer hit points the Efreet will use Flame Spell in Round 2 (allowing me to target the lower hit point enemy in contravening the normal targeting rules. If no enemy has fewer than 10 hit points, he will instead use Wall of Fire.
Raven and Phantast will just attack with their normal weapons for the first two rounds.
Decisions for Round 3 will be dependent on the resolution of Rounds 1-2.