Twilight Wave

Channeling the full power of twilight energy, you release a destructive burst that radiates outward from you. All creatures of your choice within a 15-foot radius must make a Constitution saving throw. On a failed save, they take 8d6 radiant and necrotic damage, split evenly between the two, and are stunned until the end of your next turn. On a successful save, they take half as much damage and aren’t stunned. Undead creatures and constructs take an additional 10 radiant or necrotic damage (your choice), and their speed is halved for 1 minute. 

At higher levels 

When you cast this spell using a spell slot of 4th level or higher, add 1d6 radiant and necrotic damage, split evenly between the rwo, for each slot level above 3rd.