Aegis

In a 500 feet area expanding in a sphere with the caster in the center, a spectral armour of 150 HP covers each ally, scaling  up to 150 allies depending on caster level.  Sometimes described as the perfect defence for an army commander, it boosts all defences and resistance, with the caster having an additional hp of 5 with addition of each 20 allies over 90. In the dark a spectral banner can be seen floating. Effects don't overlap if the spell is cast by multiple creatures. When broken releases a wave that deals 20d5 of psychic damage and 3d8 force damage to hostile forces, can bypass immunity.