Pact Of The Imprisoned

A shackled battery of shining radiance makes for an easygoing patron. Other warlocks sign lengthy contracts or make careless bargains, but not you. Your patron is a holy being trapped in an eternal prison, and it serves you. You spend your short rests performing profane rituals that extract magic from your patron as it rails against its bonds, desperate to be free. What a pathetic display of impotence. You are the master here.

Warlocks who take the Pact of the Imprisoned can channel the radiant energy of their unwilling patron to smite their foes with weapon and spell alike. Your signature ability is the dark sun, a globe of dire radiance that moves at your command to burn your foes, and as you steal more of your patron’s power you can channel spells through the dark sun, devastating all those foolish enough to remain nearby.

Warlock Level Feature
1st Dark Sun, Stolen Radiance
6th Infecting Light
10th Radiant Body
14th Fearsome Illumination

Dark Sun

At 1st level, you can summon the radiant power of your patron in a twisted mockery of its holy power: a dark sun of sickly light. As an action, the dark sun appears in a space you can see within 30 ft. of you. The sun is a 5-ft.-diameter sphere that does not fully occupy its space. It emits dim light in a 15-ft. radius around it. On your turn, you can spend your movement to move the sun an equivalent distance. It can fly, but if it is ever more than 120 ft. away from you, it dissolves instantly.

When the sun enters a creature’s space for the first time on a turn or a creature ends its turn in the sun’s space, the creature must succeed on a Dexterity saving throw versus your warlock spell save DC or take 1d10 radiant damage, or half as much on a success.

The sphere lasts for one minute or until you dismiss it as a bonus action. Once you have used this feature, you cannot use it again until you finish a long rest.

The sun’s damage increases to 2d10 at 6th level, 3d10 at 10th level, and 4d10 at 14th level.

Stolen Radiance

Beginning at 1st level, once per turn when you hit with a weapon or spell attack, you can change the damage dealt by that attack to radiant damage.

Infecting Light

At 6th level, you can infect a creature with a vile curse that causes it to emit sickening light. As an action, you can force a creature you can see within 120 ft. to make a Constitution saving throw versus your warlock spell save DC or it becomes vulnerable to radiant damage and sheds bright light in a 20-ft. radius. Creatures in the 20-ft. radius of bright light also become vulnerable to radiant damage.

This effect lasts for one minute and you must maintain concentration on it (as though concentrating on a spell). It ends early if the creature is slain. At the end of the affected creature’s turns, it can repeat the Constitution saving throw to end the effect.

Creatures that have resistance or immunity to radiant damage are unaffected by this ability. Once you use this feature, you can’t use it again until you finish a long rest.

Radiant Body

At 10th level, the light of your patron is used to transform your body. You gain resistance to radiant damage. Once per turn, you can expend any amount of your movement to teleport a distance equal to the movement expended to an unoccupied space you can see. You transform into a bolt of dark light, moving without provoking opportunity attacks. This doesn’t allow you to bypass magical barriers such as wall of force or forcecage.

Fearsome Illumination

At 14th level, you may combine your magic with your dark sun to devastating effect. When you cast a spell that targets only one creature and doesn’t have a range of self, you can choose to target your dark sun instead. If you do so, the spell targets each creature in the light shed by your dark sun, a radius of 15 feet. Once you have used this feature, you can’t use it again until you finish a long rest.

Ref: T&H p397-398