Breath of the Bayldri Bloodline

With this spell, The full anointed nature of your dragon soul has come to its peak maturity. The power of an ancient dragon bursts forth from you, but at what cost?

When cast this spell acts the same as an ancient Amethyst dragon breath weapon.  The caster creates a shining bead of gravitational force in its mouth, then releases the energy in a 90-foot cone. Each creature in that area must make a DC 23 Strength saving throw. On a failed save, the creature takes  18d6 force damage, and its speed becomes 0 until the start of the casters next turn. On a successful save, the creature takes half as much damage, and its speed isn’t reduced.

at higher levels the damage increases by 3d6.