Coldball

You focus magical energy into the glass sphere and hurl it towards a point in range. Upon impact the the sphere explodes in a 15 foot radius sphere and creatures caught in the explosion have to make a constitution saving throw. Taking 6d6 cold damage on a failed save and half damage on a success. Creatures killed by this spell becomes a frozen statue until it thaws.

For the next minute the area of the explosion is covered in slick ice, becoming difficult terrain. This effect can end early by dealing fire damage in the area from a spell effect of 1st level or higher.

At higher levels: When you cast this spell using a spell slot of 4th level or higher, increase the damage by 1d6 for every level abve 3rd.