The Good Sun

Your patron is the embodiment of the sun itself. Whether this eldritch being lies within the sun itself or if you are just related to it through creation or style is unknown, but you naturally feel happier under direct sunlight as its benevolent watchfulness lies upon you.

Small Flames

At 1st level, you can learn 2 cantrips from firebolt, light, dancing lights, sacred flame cantrips. They count as warlock cantrips for you but they don't count against your number of cantrips known. Also, you can choose for any of your cantrips to deal radiant damage instead of its normal fire damage.

Expanded Spell List

The tyrant sun lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Sunny Day

Starting at 1st level, while standing in direct sunlight you regain HP equal to your level every hour. You can not regain health from this ability during combat.

Also, you glow with a soft radiance. As a bonus action you can glow with a soft radiance, you glow with a bright light in a 10ft radius, with a 10ft dim light radius past that.

Gift of Warmth

Beginning at 6th level you begin to adjust to the heated nature of you patron. you gain resistance to fire and radiant damage. You are also immune to the blinded condition and the effect of extreme heat.
Also once per short or long rest you may cast the spell daylight without expending a spell slot.

Solar Flash

At 10th level, your patron has gifted you with the brightness of a sun, if only for a brief moment. As an action all creatures with in 30ft of you make a Dexterity Save at your spellcasting DC. On a failed save creatures are blinded until the beginning of you next turn and take Attack: [roll]1d20[/roll] Damage: [roll](if([roll:-1:critical], =0, 2d4, 2{2d4}.expand()))[/roll] Radiant damage. On a successful save they take no damage and are blinded until the end of your current turn. you can only use this ability once per short rest.
In addition the glow given by Sunny Day increase by 5ft for both bright and dim light and will reveal any invisible creatures to you.

Solare Flare

At 14th level you can channel the large piece of solar energy granted to you by your patron. As an action you create a narrow portal to the heart of the sun. Every creature in a 40ft cone must make a Dexterity saving throw. A creature takes Attack: [roll]1d20[/roll] Damage: [roll](if([roll:-1:critical], =0, 4d8, 2{4d8}.expand()))[/roll] and Attack: [roll]1d20[/roll] Damage: [roll](if([roll:-1:critical], =0, 4d8, 2{4d8}.expand()))[/roll] on a failed save, or half as much on a successful one.

You can use this feature once per short or long rest.