A large box, inside which a faint whirring sound can be heard. Takes 1 action to activate and 1 round to explode. All creatures within a radius of 60 feet must make a DC 16 Dexterity saving throw, creatures within 10 feet of the blast have Disadvantage on this save. Those who fail take 10d8 Radiant damage and 5d8 Fire damage as the box explodes, creatures that succeed take half damage. Objects and structures take double the damage dealt. 

Notes: Damage: Radiant, Damage: Fire