Churchbell Slam

You call forth a large bell from the heavens down upon a space within range. The bell has the effective shape of a cylinder with a radius of 5 feet and a height of 10 feet. Any large or smaller creatures within the space the bell is called down upon must succeed a dexterity saving throw or be trapped within the confines of the bell. When bell hits the ground, any creatures trapped within have total cover for the duration of the spell, and cannot concentrate on spells to a residual ringing.  The bell has a DC of 15 and 35 hit points, and the bell does not dissipate until the spell ends or hits hit points are brought to 0. When the bell falls, choose Soft Ringing, or Thunderous Clang. If you choose Soft Ringing, those within the bell or within 10 feet of it receive 3d8 hit points of healing. If you choose Thunderous Clang, those within the bell take 3d8 thunder damage, and those within 10 feet of it must make a constitution saving throw, taking 3d8 damage on a failure and half as much on a success.