Arcane Devastation

You call upon your arcane prowess to launch a beam of pure arcane energy. When you cast this spell  in a 10ft by 50ft the area is completely covered by the purple beam. firing this all creatures in the area when cast, enter the area for the first time, or end their turn there must make a constitution save or take 10d8 force damage or half as much on a successful save. Movement inside the beam is treated as rough terrain as the force of Concentrated energy pushes on the creature. Every turn that the spell is still active the caster can move the area covered  by the spell but must not move from where they and use their action to maintain the effect as well.