Devah's Unrelenting Force

A wave of arcane force expels from the caster in all directions. Any creatures within 20 feet of the caster when cast must make a Strength saving throw. Creatures in range take 3d10 force damage and are pushed back 10 feet. On a successful save a creature takes half damage and is not pushed. Until the spell ends, using an action, the caster can continue to expel smaller waves of force 10 feet in all directions dealing 2d10 damage and pushing back 5 feet. For each level above 3rd this spell is cast at, both the initial wave and subsequent waves increase damage by 1d10.