Wayland's Flaming Mortar

The Caster imbues the pipe with arcane fire. For the duration, the caster may take an action to strike the flint against the base of the pipe and fire a volley of fiery projectiles. Choose two points within range. All creatures within 5 feet of of either point must make DEX saving throws, taking 2d8 fire damage on a failed save, or half on a success. All flammable objects not currently held or worn catch ablaze. At the end of the duration,  if the caster has not chosen the maximum number of points possible, or if the caster loses concentration, the focus detonates and deals 3d6 fire damage in a 10 foot sphere, centered on the caster.