Plane Slayer

Plane Slayers are fighters that have been trained to take down creatures from beyond the mortal realm. While Rangers track and hunt, Plane Slayers are the infantry that are sent in to deal with an outer-planer army or are there to supplement Paladins, Rangers or Clerics who might be on a personal or holy quest to take down these creatures. Initiates of this archetype are taught a range of fighting styles, skillfully keeping their foes at bay and protecting those with them. Some Plane Slayers are even augmented physically to be the perfect killing machines of outer-planer beings. With Plane Slayers only one thing is certain, an outer-planer creature will not be walking away from them.

Talk with your DM and decide if your character has been augmented physically. Augmentations might include: inability to feel the heat or the cold (for example for a Plane slayer of a creature from the realm of fire), darkvision of 60ft if your character does not already possess this or limb enhancements to make travel in such a plane easier (this can either be from a roleplaying perspective or mechanics perspective). If your character does possess any augmentations, how were these given to them? Was it through training or experimentation?  How does your character feel about these augmentations?

 Plane Slayer Features

Fighter Level	Features
3rd	Conditioning, Slayer's knowledge
7th	Teamwork
10th	Additional Fighting Style
15th	Battlefield Mastery
17th	Expert Slayer

Conditioning

You have been specifically trained to fight against one type of enemy. When fighting that enemy, you can take a bonus action to remember your training and do a contested athletics check against the enemy's deception. If you beat their DC, until you take a long rest, you gain advantage when attacking that type of enemy, and you can take a reaction to attempt to block their attack when they attack you or an ally. You roll to hit and if you roll higher than they did, then you can completely block their attack. If you roll the same you can add a +2 to that person's AC, potentially turning a hit into a miss. 

Once your favoured type of enemy has been chosen it cannot be changed.

Slayer's knowledge

You have advantage when doing a history or intelligence check to try and recall information about your favoured enemy and their home terrain. Unlike with rangers, this knowledge tends to be solely about weaknesses or specifically difficult terrain and not about things such as eating habits or flora and fauna of the terrain. 

Teamwork

Starting at 7th level, when you have advantage attacking an enemy and make a successful attack, any ally within 5ft of you can use their reaction to attack the same enemy. 

Additional Fighting Style

At 10th level, you can choose a second option from the Fighting Style class feature.

Archery

You gain a +2 bonus to attack rolls you make with ranged weapons.

Defense

While you are wearing armor, you gain a +1 bonus to AC.

Dueling

When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.

Great Weapon Fighting

When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.

Protection

When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.

Two-Weapon Fighting

When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.

Battlefield Mastery

Starting at 15th level, if you take the attack action on your turn and have advantage on the attack roll against against one of the targets, you can forgo the advantage for that roll to make an additional weapon attack against that target as part of the same action. Alternatively, once you have taken an attack with advantage, you can move up to your movement in any direction without evoking any opportunity attacks.

Survivor

At 18th level, you are a survivor used to travelling around and hunting your favoured enemy. The amount of time you can go without food and water doubles, the amount of time you can hold your breath also doubles, you have immunity to disease, and resistance to poison and the damage most commonly dealt my your favoured enemy.