By far the easiest is 4 reds and a dismounted healer. Remember to take the healer off follow and to fly your group up to just within healing range. Save evasion for the astral shifts when he's within 15% of the shift times (60% and 20%) and you won't have to move your dragons at all. Heal your healer the second they get hit. You may have to use mana return tools midway through the fight (big mana return totem or hymn).

Good luck!