Serpent & Cross

Rangers of the Order of the Serpent & Cross study intricate and vague lore found in the forgotten corners of the world. They've built Hidden Lodges to train their members in seclusion before sending them out to guard and protect those who find themselves defenseless in the wilderness, be they mortal, spirit or fey, or to seek more lore to guard and keep for their order - and seal away the obscure, dark practices that threaten innocence.

Utilizing the Spirit Guardians spell to strange and wonderful alterations along with unparalleled skill with Crossbows, these rangers become a nightmare on the battlefield, and a boon to their allies by either controlling the flow of battle, or by bolstering the defenses of their allies.

Cross's Oath

Starting at 3rd Level you gain Proficiency in Crossbows of all types, as well as the Feat Crossbow Expert.
You also gain Proficiency in Charisma Ability Checks.

Serpent's Domain

At 7th level, you can Cast the  Spirit Guardians Spell as a Ranger Spell without Expending a Spell slot once per short- or long Rest. Additionally you can spend one of your ranger spell slots of appropriate level to up-cast this spell. 
You also gain one of the following features as an augmentation to they aura of your Spirit Guardians.

Cloak of Swiftness

When you cast the Spirit Guardians, you gain 10 ft of movement at the start of each of your turns for the next 2 turns. You can also use this 10 ft as Climbing speed or leap distance for the duration. 

Crossbow Trick

Once per round, when a creature hits you with a melee attack and they remain within 10 ft of you, you gain a +4 bonus to hit the next Crossbow Bolt you fire at that target. Additionally, if your Spirit Guardians is up, and that target is within it's area of effect, they have disadvantage on the next Saving Throw it makes against the spell's damage. 

Spirit's Aim

If your Spirit Guardians are up, you gain +2 to hit anyone within the area of effect of Spirit Guardians. Additionally you can expend a spell slot to gain +2 poison damage of each of your attacks you make with a Crossbow for one round. You may use this additional feature twice per long rest.

Ancient Guardians

At 11th level, you gain one of the following features of your choice that further Augment your  Spirit Guardians and the aura they provide. Additionally whenever you have to roll a Concentration check to keep your Spirit Guardians, you may expend one spell slot of any level to automatically succeed the check.

Nurturing Spirits

Whenever you Spirit Guardians spell is active, allies within the range of this spell heal for 1d4 hit points whenever an enemy dies as a direct result of your Spirit Guardians. Additionally you may expend one spell slot of any level to curse one enemy within range of your Spirit Guardians. If this foe starts their turn within your aura's range, they have their movement speed halved for that turn. You may curse a target like this twice per long rest.

Serpent's Tomb

For every Foe that is slain as a direct result of your Spirit Guardians, the Range of Spirit Guardians Increases with 5ft up to a maximum of 15ft. This Effect Lasts up to 5 Minutes or Until the Spell Fades.

Additionally you may expend one spell slot to bolster your Spirit Guardians gaining an additional 1d4 Poison Damage to the next roll you make for the spell's damage. You may bolster your aura in this manner only twice per long rest.

Vigilance

Each Ally within Range of your Spirit Guardians Area of Effect Gains +1 to their AC, including you. Should your Spirit Guardians deliver the killing blow to a foe, the bonus goes up to +2 but cannot exceed +2 should another Enemy fall. This buff ends when your Spirit Guardians ends.

Master Arbalist

At 15th level, you gain one of the following features of your choice. This further Augments your  Spirit Guardians to devastating heights. 
Furthermore, your Spirit Guardians no longer take up concentration. You can now cast Spirit Guardians and it will remain without the need to make Wisdom saving throws for concentration. You can now cast a concentration spell without losing your Spirit Guardians.

Coiling Strike

When an attacker that you can see hits you with a melee attack, you can use your reaction to perform a Melee attack on the attacker using your Crossbow. This attack deals 2d8 Bludgeoning Damage and the attacker must make a successful Contested Strength check or be stunned and be pushed back 10 ft. If your Spirit Guardians are up, you can 1d4 poison damage to this attack. You may use this feature up to a number of times equal to 1+ your Wisdom modifier per long rest.

Intimidating Presence

When a hostile creature misses you with a melee attack, you can use your reaction to impose disadvantage on that Creature's next attack. You glare at the attacker, reloading your crossbow in an intimidating fashion. If your aura of Spirit Guardians is up, the Creature also has to make a successful Wisdom Saving throw or have disadvantage on all attacks it makes while they are within range of you Spirit Guardians. You may use this feature up to a number of times equal to 1+ your Wisdom modifier per long rest.

Slumbering Scales

When you are subjected to an effect, such as a red dragon’s fiery breath or a lightning bolt spell, that allows you to makes a DEX saving throw, you may consume one spell slot to grant yourself and 1 ally within range of your  Spirit Guardians, Resistance to the incoming damage type. This buff remains on you until your Spirit Guardians fade. You can only buff an ally this way if your Spirit Guardians are up. The victim has disadvantage on all it's attacks while remaining within the aura. You can use this feature up to an amount of times equal to 1+ your Wisdom modifier per long rest.