Tsunami

Duration: 6 rounds, Concentration
A giant wave forms, it is up to 300 ft long, 300 ft
high, and 50 ft thick. Each creature within it's
area makes a Str save, it takes 6d10 bludgeoning
damage, or half on a success. At the start of your
turn, the wave and it's content moves 50 ft away.
Creatures inside make Str saves or take 5d10
bludgeoning damage. At the end of turn, the
height decreases by 50 ft, and the damage is also
reduced by 1d10. Creatures can swim in the wave
with an Athl