Black Pillar

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.