Way of the Guardian

Designated Aegis
At level 3, as part of a long rest, you may designate a shield in your possession as your Guardian's Shield. You gain proficiency in using that shield, and your Guardian's Shield may be used with Unarmored Defense and other monk abilities, without penalty. You may attack with your shield as though it were a monk weapon, and it deals the appropriate type of damage (bludgeoning for a simple bash, slashing if its sides are bladed, piercing if the shield is spiked). The damage is equal to your martial arts dice.

Patient Bulwark
At level 3, you gain the following features while in possession of your Guardian's Shield:
 * You have advantage on checks and saves to resist being grappled, forcibly moved or knocked prone.
 * You may, as a reaction, impose disadvantage on an attack against a creature other than you, so long as you are within 5ft of the creature being attacked.

Thrown Aegis
At level 6, your shield can be used as a thrown weapon (with a range of 30/90). If your last attack with the shield misses, it doesn't return to you until the beginning of your next turn, otherwise it returns to you immediately after the last attack, provided you have an empty hand and it has a clear path. If you hit a creature that has cover roll a d100 if they have half cover your shield returns back to you on a 50 or higher if they have three quarters cover it returns on a 75 or higher.

You can ricochet your shield for additional attacks against creatures within range using your Extra Attack or additional attacks by other means such as a haste spell.

Attacks made with your shield are considered magical for purposes of overcoming resistance and immunity.

Guardian's Defense
At level 11, you can spend an amount of ki to cast certain spells as a bonus action. Compelled Duel for 3 ki, Warding Bond for 5 ki or haste for 9 ki and you can cast levitate at will but only on your Guardian's Shield.

Bastion of Ki
At level 17, while holding your Guardian's Shield, you gain resistance to nonmagical bludgeoning, slashing and piercing damage, and you also gain the ability to before a long rest store an amount of ki equal to half your monk level for use until the next long rest.