Solar Paladin (Oath of Radiance)

An Oath of Radiance paladin has sworn to eradicate evil and replace it with light. They use their fiery radiance to cleanse the darkness wherever they go, believing that the pure and potent power of the sun is above all and those who don’t wish to bask in its glory should suffer in its heat.

The spell list is included here to avoid any issues with DnD beyond flagging spells outside the PHB

Oath of Radiance spells

• Paladin Level 3: Hellish Rebuke, Searing Smite
• Paladin Level 5: Aganazzars Scorcher, Heat Metal
• Paladin Level 9: Fireball, Daylight
• Paladin Level 13: Death Ward, Fire Shield
• Paladin Level 17: Dawn, Destructive wave (An Oath of Radiance exclusive version that deals a combination of radiant and fire instead of thunder/necrotic)

Level 3: Level 3 – Bathed in flames

You gain immunity to fire damage that originates from your own spells. You also know the absorb elements spell (fire only) and can use the spell a number of times equal to your proficiency bonus every short/long rest without the use of a spell slot.

Level 3: Level 3 – Explosive Smite

Immediately after you cast divine smite, you can expend one use of your channel divinity charges to cause a solar explosion at the targeted creatures location. All creatures within 10ft of the targeted creature take 1D6 + paladin level fire damage (or half as much on a successful dexterity saving throw).

Level 3 – Cauterizing Hands

Whenever you use your lay-on-hands to heal an ally the intense heat helps to seal their wounds. If the Ally is suffering any negative effects from being cold/frozen those effects end immediately and they also gain resistance to physical damage for the first attack that hits them on their next turn

Level 7: Level 7 – Aura of Radiance

Your aura of protection becomes charged with radiant heat. Enemies take 1D4+cha fire damage upon entering the aura as well as 1D4+cha fire damage at the start of each of their turns inside the aura.

Level 15: Level 15 – Chain Reaction

All fire and radiant damage that you deal ignore resistance to those damage types. Additionally, if you kill a creature using either a spell or an attack that includes fire or radiant damage, you can use a reaction to make the enemy explode. All creatures within 5ft of the enemy take 1D8 fire + 1D8 radiant damage or half as much on a successful dexterity saving throw (DC = 8 +charisma + proficiency).

Level 20: Level 20 – Being of Flame

As a bonus action you can ignite your Aura of Radiance with an extra intensity for 1 minute, granting the following effects. You can use this feature once per long rest.

• its damage to increase to 1D8+cha
• whenever you attack an enemy within the aura, they take extra fire damage equal to your charisma modifier
• you become immune to all fire damage
• You radiate such intense light that enemies who enter the aura must make a DC 12 dexterity save or be blinded for 2 turns