Black Pillar

A monument, they said to him. Thus it was built, but like no other they had seen. To this day, they regret their request.
You gesture to the ground and speak an incantation, calling a pillar of stone to rise from the earth at a location within range. The pillar is 15 feet tall, 5 feet on each side, covered in cruel spikes, and has a flat top that can be safely stood upon. If a creature is caught between the pillar and another surface, such as a ceiling, they must make a Dexterity saving throw. If they fail, they take 2d10 bludgeoning damage and fall prone in the nearest open space. If a creature is shoved or pushed against the sides of the pillar, they take 1d6 piercing damage. The pillar can be climbed safely by making an Athletics check with a DC equal to your spell save DC. The pillar has hit points equal to fifteen times your spellcasting modifier (minimum 15), 10 AC, and is permanent unless dispelled.