When you choose the Oath of the Watchers as your Subclass option, you make an oath with the following tenets:
Defy Horror. You can not allow horror to take place. Not here, not now, not ever.
Punishment First. No mercy for the wicked.
Steadfast. Your enemy never rests, neither should you.
Zeal of Purity. Monsters lacks empathy. Have none, show none.
If you willfully violate these tenets and show no sign of repentance, your Subclass option is replaced with the Oathbreaker option.
You inherit the spells at each indicated paladin level in the Oath of the Watchers Spells table as paladin spells.
When you cast the divine smite spell, you can increase its damage die by one size for its duration.
Once you use this feature, you can't use it again until you finish a long rest, unless you expend one use of your Channel Divinity feature.
You can take the Magic action to cause one creature that you can see within 120 feet of you to make a Wisdom saving throw. On a failed save, the target becomes immobilized for one minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Once you use this feature, you can't use it again until you finish a long rest, unless you expend one use of your Channel Divinity feature.
You have an aura (10 feet) that allows you or any friendly creature that is under an effect that allows it to repeat a saving throw at the end of its turn to instead make the roll at the start of the turn.
The aura increases by 10 feet as a level 10 (20 feet) and 18 (30 feet) paladin.
Once on each of your turns, when you take the Attack action and hit, you can deal an additional 1d8 radiant damage. If you have advantage on the attack roll and the lower of the two d20 would also hit, the target becomes your choice of hindered or maimed until the start of your next turn.
You are immune to divination spells and effects that originate from aberrations, celestials, elementals, fey, fiends, and monstrosities.
You can take the Magic action to gain the following effects for 1 minute:
Aberrations, celestials, elementals, fey, fiends, and monstrosities are staggered against you.
You are immune to the charmed, dazed, freightened, impaired, and paralyzed conditions caused by an effect that originates from an aberrations, celestials, elementals, fey, fiends, and monstrosities.
You are immune to necrotic damage.
When an aberration, celestial, elemental, fae, fiend, or monstrosity causes you to make a saving throw, you have advantage on the roll.
Once you use this feature, you can't use it again until you finish a long rest, unless you expend one use of your Channel Divinity feature.