Black Hole

You manifest a tiny pinpoint black dot in space, which rapidly grows as you concentrate on it. All creatures within 60 ft of the bead must make a Dexterity saving throw, or begin to be pulled to the point at 15 ft per turn. Being within 20 ft of the point deals 5d10 bludgeoning damage per turn, which increases by 5d10 per 5 ft closer to the point. Creatures can move at half speed when within the 60 ft zone, and all projectiles, spells, and other ranged attacks or effects are canceled, and sucked into the point. 

At the end of 1 minute, the point vanishes peacefully, or when the caster loses concentration, the point collapses, and explodes, dealing 20d10 thunder and 20d10 force damage to all within 150 ft. of itself. The caster can force a failed con to save, to detonate it themself. This explosion of gravitational energy can destroy structures, objects, and non-magical items.