Guardian domain

Guardian clerics devote themselves to protecting anyone who would look to them as defenders.  The Guardian cleric (often just addressed as Guardians) can serve almost any divine being, but due to the selfless nature of a guardian, most worship good or lawful deities. A guardian under the worship of Melora may be tasked to protect seaports from pirates. Perhaps a follower of Erathis may shield a city from a great evil. Overall a guardian may follow any deity as long as that being's word is heeded. Guardians are fierce protectors who will put everything including themselves at risk to keep allies and innocents safe.

Bonus proficiancy

When you choose this domain at 1st level, you gain proficiancy with heavy armor and martial weapons.

Defender

At 1st level you may strike a foe that would pose a danger to an ally. When an ally within 30 feet of you is attacked you may use your reaction to impose disadvantage on the attack as well as deal 2d8 radiant damage. The target must make a dexterity saving throw to take half damage.

You can use this feature a number of times equal to your wisdom modifier (a minimum of once). You regain all expended uses when you finish a long rest.

Channel Divinity: Speed of the Protector

Starting at second level, you can use your channel divinity to apperate at the side of an ally in order to protect them. As a bonus action you may teleport to an adjacent space next to an ally within your line of sight and make a single weapon attack against a foe.

Defender's Aura

At 6th level your very presence is enough to defend the innocent from any that would do them harm. As an action you may add your Wisdom modifier to the AC of all allies within a 30ft radius. This bonus is not given to you. This ability is concentration.

Divine Strike

At 8th level, you gain the ability to infuse your weapon strikes with divine energy. On each of your turns when you strike a creature with a weapon attack, you can cause the attack to deal an extra 1d8 radiant damage to the target. When you reach 14th level, the extra damage increases to 2d8.

The Unyielding Guardian

At level 17 you become a vessel of true defense and you are able to come to the people's aid at blinding speed. Your base speed is tripled and you gain an additional attack.