Oath of a Pure Heart

Through many struggles, you have overcome each one by promising to do what is best. Knowing that no matter what, you must keep a level head and a kind heart. 
Your heart of gold, along with your strong mind gives you powers related to your psyche, almost alien in origin. 

Level 3: Oath of a Pure Heart Spells

The magic of your oath ensures you have the ability to prepare certain spells. You may prepare spells from the sorcerer class, and cast them using charisma as your ability.
The magic from casting comes from your inner mind, your psychic powers allowing you the use of magic from your imagination. 

You may also choose to change the damage of your Divine Smite from Radiant to Psychic.

Level 3: Psionic Strikes

When you take the Attack action, you can expend one use of your Channel Divinity to imbue one Melee weapon that you are holding with your psionic strength. For 10 minutes or until you use this feature again, your damage does extra psychic damage equal to your spell modifier. 

If you are disarmed from this weapon at any time, you can use a bonus action to call it back to you. You always know where this weapon is.

You can end this effect early (no action required).

Level 7: Aura of a Pure Heart

The light of your pure heart shines on your party! When allies are in your Aura of protection, they take 1d6 less damage when targeted by all attacks. This increases up to 1d12 at level 15 and 1d20 at level 20.

Level 15: PSI Burst

Whenever you hit a creature with your weapon imbued from Psionic Strikes and choose to cast the Divine Smite spell, the psionic energy leaps out towards nearby creatures, you may deal damage equal to the amount of damage done with the attack to the new creature. The psionic energy can leap up to 10ft each time and does so an amount of times equal to half your proficiency bonus rounded down, without targeting the same creature twice. As you continue to accumulate understanding with psionic energy, the distance it can leap increases to 15ft at level 17, 20ft at level 20.

Level 20: Plethora of Kindness

As a Bonus Action, you can imbue your Aura of Protection with holy power, granting the benefits below for 10 minutes or until you end them (no action required). Once you use this feature, you can’t use it again until you finish a Long Rest. You can also restore your use of it by expending a level 5 spell slot (no action required).

Bein' Friends! If an ally in your Aura of Protection consumes a spell slot for any purpose, you can choose to (No reaction needed) expend the spell slot from your own supply.

SMAaAaAaSH!  Allies' unarmed strikes and weapon attacks in your Aura of Protection do an extra 2d10 psychic damage once per turn.

Guts! Any ally in your Aura of Protection has advantage on death saving throws. Any rolled 19 on a death saving throw while in the aura is treated as a 20.