Paladin
Oath of destruction
The oath of destruction are paladins who commit to the essence of pure destruction. All they believe is that their enemies are no better than the ash you will reduce them to.

Tenants of Destruction

Let fire rein
Those who oppose you must fall along with everything they love.

Destruction is life
You are destruction in its purest form, let no one stand in your way.

Oath of Destruction spells
Paladin level - spells
3rd - Thunderwave, Inflict wounds
5th - Shatter, Scorching ray
9th - Fireball, Call lightning
13th - Vitriolic Sphere (XGE), Ice storm
17th - Cloudkill, Destructive wave

Channel divinity: Destructive smite
Starting at the 3rd level, when you activate your divine smite you can use your channel divinity to deal maximum damage with the extra radiant damage.

Channel divinity: Burn it all
Starting at the 3rd level, you can use your channel divinity to cause flammable objects of your choice that are not being worn or carried in a 20 foot sphere centered on you to ignite. Any creature who steps into the area of your created flames or ends their turn there takes 1d6 fire damage and an extra 1d6 radiant damage.

Aura of Destruction
Starting at the 7th level, you emit an aura of destruction that extends 10 feet around yourself. Whenever a creature of your choice makes an attack roll in this aura, their damage roll increases by 4.
Starting at the 18th level, this aura becomes 30 feet instead of 10 feet.

Unyielding smite
Starting at the 15th level, your spells and weapon attacks ignore resistance to their respective damage.

Being of destruction
Starting at the 20th level, you can access a form of pure destruction as an action. For the next minute:
-Your attack rolls and spells ignore resistance and immunity.
-Your weapon damage rolls deal maximum damage.
-You deal triple damage to objects and structures with your weapons and spells.
Once you use this feature you may not use it again until you complete a long rest.