Remote Bomb

You can activate and place this bomb at yuor feet or up to 5 feet away from you as an action on your turn. As a bonus action any time from the turn you activated the bomb up to an minute, you can say a command word and the bomb will detonate.
  The bomb will detonate without the command word if you move more than 110 feet from the bomb, if more than a minute has passed since activation, or if the bomb takes damage.
  Upon detonation, each creature in a 5-foot-radius from the bomb must make a DC 10 Dexterity saving throw, taking 2d6 damage on a failed save or half that damage on a successful one. Half of the damage is thunder damage, and the other half is fire damage.