The Kingmaker

Prerequisite: Pact of the Chain Warlock. You cannot take this subclass unless you are to take the Pact of the Chain feature at Third Level. 
Kingmakers are ancient beings of great power, varying in size, strength, intelligence and capabilities. However, they all share the ability to make a bond- a Kingsbond, with those they deem worthy of revelling in their power. A kingmaker serves as divine proof of the right to rule, and lends their power to their chosen king to protect their homeland. Provided the bond with the kingmaker is strong, and based upon trust and loyalty, no mortal army could face up to you. 

The loyalty of a kingmaker can be earned in many fashions. Traditionally, the kingmaker is tamed by a strong display of power, demonstrating the potential ruler's prowess and strength, although force is not the only means to prove your worth. The kingmaker could be earned through hereditary succession, or even any small but acceptable demonstration of your ability to rule. A kingmaker unassigned to a current ruler resides in its cradle, to which prospective rulers can visit and attempt the trials to prove themselves. In this day and age, there are few unclaimed Kingmakers.

Bond of Radiance

Whenever you gain a spell in the Warlock class, you can instead choose to take a spell from the Paladin spell list. This does not apply to your Mystic Arcanum.

Spirit of a King

For one minute, you enter the state of the Kingsbond. You can do so an amount of times equal to your proficiency modifier. While in this state, you gain the following benefits; 

• You gain advantage on Charisma ability checks (Persuasion)
• When you cast a spell at first level or higher, any allies within 10 feet of you gain an amount of HP equal to the spell's level plus your warlock level.
• Once per short rest, when you enter this state, you can call upon the power of your Kingmaker, and restore a single spell slot, of which the level can be no higher than half your Warlock level (rounded down), for any creature that you can see within 60 feet.

Kingmakers Call

Your connection to your Kingmaker has developed to the point where you can entreat upon its power to embolden your allies. When an allied creature enters within 15 feet of your chain familiar, they gain an amount of temporary HP equal to your Warlock level. Additionally, once per long rest, your Kingmaker can cast a spell that you know, from the Paladin spell list without expending a spell slot. If the spell requires concentration, the Kingmaker makes this check, adding your spellcasting modifier to the total. 

Radiant Fury of the Kingsbond

Your bond with your Kingmaker has grown exponentially. Your combined power radiates the battlefield like a glowing lantern. When you enter the Kingstate, you gain an amount of temporary HP equal to double your Warlock level. Additionally, while you are in the Kingstate and are within 5 feet of your chain familiar, your armour class increases by your proficiency bonus (rounded down).

The Trust of a True King

Starting at 14th level, you gain the ability to assimilate with your kingsmaker chain familiar. As an action you call onto your chain familiar, which immediately drops to 0 hit points and disappears filling you with a tremendous power. You gain the following benefits for the next hour, or until you use an action (1 minute) to re-summon your familiar,

• Your maximum hit points increase by an amount equal to the total amount of spells you know.
• You deal an additional 1d10 Radiant damage when you land a successful attack roll.