Chosen of Amaunator

Amaunator has chosen you as his champion, granting you various abiltites and natural boons related to his domain of light and sun.

Radiant Aura:

You shimmer, the power of Amaunator manifesting physically. Whenever a creature of darkness (fiend or undead) starts its turn within 5 feet of you, it takes radiant damage equal to your level plus your Wisdom modifier.

Additionally, any time you are in complete darkness, you can shed bright light in a 20-foot radius and dim light for an additional 20 feet. If the darkness is magical, you shed bright light in a 10-foot radius and dim light for an additional 10 feet.

This effect must be concentrated on to be maintained, and ends when the chosen loses that concentration (either by casting a concentration spell or taking damage) or dismisses it as an action.

Armor of the Sun:

You are immune to radiant damage, and have resistance to fire and cold damage.

Additionally, whenever a hostile creatures damages you with an attack, you can use your reaction to deal fire damage equal to 1d6 plus your Wisdom ability modifier. The damage increases as you gain levels: 1d8 at 5th level, 1d10 at 11th level, and 1d12 at 17th level.

Amaunator's Wrath:

As an action, you can expand your Radiant Aura. When you do so, any creatures within 30 feet of you must succeed on a Constitution saving throw or become blinded for one minute. On a failed save, a creature also takes 2d8 radiant damage, or half as much on a successful save. Creatures that are already blinded or do not rely on traditional sight (such as a creature that relies only on blindsight) are immune to this effect.

Once you use this ability, you cannot use it again until the next dawn.

Amaunator's Vengeance:

Whenever a hostile creature drops you to 0 hit points, you can use your reaction to instead regain half your hit point maximum, rounded up. Your eyes burn with righteous fire, and you become a whirlwind of unstoppable fury. For one minute, you have advantage on all attack rolls, and any creature targeted by a damaging spell cast by you has disadvantage on their saving throw. You also gain an additional 10 feet of movement and resistance to all damage for the duration.

After one minute, the fire extinguishes, and you immediately suffer two levels of exhaustion as the divine energy coursing through you takes its toll. Once you use this ability, it cannot be used again for seven days.