Whirlwind of Fire

You conjure a pillar of flame at a point you can see within range. The pillar is five feet across and ten feet tall. Whenever a creature moves into the affected area or starts it's turn there, it must succeed on a dexterity saving throw or take 1D6 fire damage. On your turn, you can use a bonus action to move the pillar up to 30ft in any direction. If the pillar is ever more than 30ft away from you, it disappears. When you cast this spell, you may expend any number of additional spell slots. If you do, the amount of damage dice increases by (the number of additional spell slots expended + the total level of additional spell slots expended).