Armored Formation(Kobold Press)

This spell is From Kobold Press: Tome Of Heroes 5E.

You bolster the defenses of those nearby. Choose up to twelve willing creatures in range. When an affected creature is within 5 feet of at least one other affected creature, the create a formation. the formation must be a continuous grouping of affected creatures, and each creature must be within 5 feet of at least one other affected creature within the formation. If the ever has less than two affected creatures, it ends, and an affected creature that moves further that 5 feet from other creatures in formation is no longer in that formation. Affected creatures don't all have to be in the same formation, and they can create or end as many of various sizes as they want for the duration of the spell. Each Creature in a formation gains a bonus depending on how many affected creatures are in that formation.

Two or More Creatures. Each Creature Gains +2 bonus to AC.

Four or More Creatures. Each Creature Gains +2 bonus to AC, and when they hit with any weapon, it deals an extra 1d6 damage of the weapons Type.

Six or More Creatures. Each Creature Gains +3 bonus to AC, and when they hit with any weapon, it deals an extra 2d6 damage of the weapons Type.