Twister of Flame

When you start spinning your hands and saying the words for this spell, the material items for it disappear and turn into flames. These flames fly in front of you and start spinning, forming a tornado that is  25 feet wide and 50 feet tall, spinning and charging up for 2 actions. On the second action, you can choose to send this tornado in any direction in 70 feet, as long as you are facing that direction. If a target is in front of the said tornado, the targeted creature must make a dexterity saving throw of 12 or take half the fire damage. The maximum damage the tornado can do is 4d8+2 fire damage, half of that being 17 damage. This spell can be used at higher levels and gains more range, saving throw sum, and damage when used at these higher spell slots.

At Higher Levels. 

For every spell slot, you use at a higher level, one dice is added to the total amount. Also, starting at level 6 spell slots, the saving throw of 12 gets a plus +1 every time the level increases. The range also increases by 10 feet every spell slot level increase. The width of the tornado stays the same, but the height increases by 5 every time it is cast at a higher level.