Conjure Mountain

Summon a 10 by 10 feet wide spike of stone that reaches between 5 and 20 feet upwards, length is decided when you cast the spell. Any creature in the area of the spike when it is summoned makes a dexterity saving throw. On a fail, the creature takes 3d10 bludgeoning damage as the stone slams into them. On a success, they take half of that. The area occupied by the spike is impassable, and it can be used as cover. When cast at higher levels, damage increases by 1d10 per level and it lasts for one more round per level.