Horizon Walker

Adopted from Taron "Indestructoboy" Pounds
Horizon Walkers guard the world against threats that originate from other planes or that seek to ravage the mortal realm with otherworldly magic. They seek out planar portals and keep watch over them, venturing to the Inner Planes and the Outer Planes as needed to pursue their foes. These rangers are also friends to any forces in the multiverse—especially benevolent dragons, fey, and elementals—that work to preserve life and the order of the planes.  

Detect Portal

3rd-level Horizon Walker feature   You gain the ability to magically sense the presence of portals. As an Action, you detect the distance and direction to the closest planar portal within 1 mile of you, as well as the number of portals that have been opened and closed within 500 feet of you in the last 24 hours. Once you use this feature, you can’t use it again until you finish a Short or Long Rest.   See the “Planar Travel” section in chapter 2 of the DMG for examples of planar portals.  

Planar Warrior

3rd-level Horizon Walker feature   As a Bonus Action, you can draw on the extraplanar energy of the world to enhance a weapon you are wielding. For 1 minute, all damage dealt by the weapon becomes Force Damage, and it deals an extra 1d6 Force Damage against creatures marked by your Hunter’s Mark spell. This benefit ends early if you end your turn while not holding the weapon.  

Temporal Snare

3rd-level Horizon Walker feature   When a creature within 60 feet of you that you can see attempts to open a portal or teleport using a spell of a level equal to half your Ranger level or lower (maximum of 9th level spell) or move through an object or structure (such as with the Incorporeal Movement trait), you can use your Reaction to force them to succeed on a Charisma Saving Throw against a DC equal to 8 + your Wisdom modifier + your Proficiency Bonus. On a failure, the creature takes 1d10 Force Damage, is shunted 10 feet away from its current position to the nearest unoccupied space, and any spell they cast that triggered this Reaction ends.   Once you use this feature, you can’t do so again until you finish a Short or Long Rest.  

Ethereal Step

7th-level Horizon Walker feature   As a Bonus Action, you can cast the Etherealness spell with this feature, without expending a Spell Slot, but the spell ends at the end of the current turn. You can use this feature a number of times equal to your Proficiency Bonus, and you regain all expended uses when you finish a Long Rest.  

Distant Strike

11th-level Horizon Walker feature   You gain the ability to pass between the planes in the blink of an eye. When you take the Attack action, you can teleport up to 10 feet before each attack to an unoccupied space you can see.   If you attack at least two different creatures after teleporting this way, you can make one additional attack as part of the same action against a third creature.  

Spectral Defense

15th-level Horizon Walker feature   Your ability to move between planes enables you to slip through the planar boundaries to lessen the harm done to you during battle. When you take damage from an attack, you can use your Reaction to give yourself Resistance to all of that attack’s damage on this turn.