Sentinel (5A)

This is a Fighter subclass for 5A

Source: Ensider 151.

A wall to your back is just as good as another sword arm, for you excel where other warriors find their techniques hampered by a low ceiling or narrow hallway.

Flanked Defense

Beginning when you choose this archetype at 3rd level, you gain a +2 bonus to AC while within 5 feet of an ally or wall. Additionally, you gain advantage on checks made to avoid being disarmed, fall prone, or resist a shove while adjacent to a wall or an ally.

Lunging Protector

Starting at 7th level, you master a broad stride and adroit footwork that grants you an undeniable tactical mobility. While you benefit from the Flanked Defense feature, all adjacent allies gain a +1 bonus to AC. If you have the Protection Fighting Style, you may use it to benefit allies within 10 feet instead of 5 feet.

Back to the Wall

At 10th level, when within 5 feet of a wall, you gain additional advantages.

You cannot be surprised.
If the flanking rule is used you cannot be flanked.
You are immune to the prone and restrained conditions and cannot have your speed reduced.

Strike from the Wall

Beginning at 15th level, while within 5 feet of a wall you deal additional damage equal to your Proficiency Bonus on your first attack each turn. While within 5 feet of a wall on two or more sides, you deal this damage on all attacks.

They Have My Back

Starting at 18th level, your allies are considered walls for the purpose of your Sentinel class features.

Paladin Sacred Oath: Oath of Discovery

Many a knight finds that questing for knowledge is one of the noblest pursuits, ultimately devoting their lives to the task of discovery. Orders of these warriors operate from libraries and royal archives, engaging in study and defending their fellow scholars when they are not searching the world for answers to its mysteries.

Oath of Discovery

A paladin that has taken this oath leaves no stone unturned and considers no secret to be truly forbidden!

Tenets of Discovery

Knowledge Above All. Your life is nothing compared to the world’s memories.
Responsibility. Any great evils or changes caused by your quests are yours to fix.
Thoroughness. An unturned stone is as vile as an enemy that destroys knowledge.
Trailblazer. Exploration is the most revered path to glory.
Uncover Mystery. Forbidden knowledge is only information privy to those worthy of knowing it.

Oath Spells

Level Spells 3rd comprehend languages, identify 5th augury, see invisibility 9th clairvoyance, tongues 13th arcane eye, divination 17th legend lore, scrying Channel Divinity When you take this oath at 3rd level, you gain the following two Channel Divinity options.

Discern Weakness. As an action, you can learn the resistances, immunities, abilities, and attacks of any creature with a challenge rating no higher than your character level + 2. You must be able to see or hear the target and the full breadth of what you learn is at the discretion of the GM (particularly obscure monsters may reveal very little).
Spirit of Discovery. As an action, you gain advantage on and double your proficiency bonus to a check made to gather information or for any ability check you make that uses Arcana, History, Insight, Investigation, Nature, or Religion.

Aura of Mindfulness

Starting at 7th level, you and friendly creatures within 10 feet of you gain resistance to psychic damage and advantage on one type of mental saving throw while you are conscious. You choose which saving throw (Intelligence, Wisdom, or Charisma) each time you finish a short or long rest. At 18th level, the range of this aura increases to 30 feet.

Inquisitive Mind

Beginning at 15th level, you are immune to the charmed condition, immediately receive a saving throw with advantage to when you see an illusion to see through it (without having to spend an action to assess it). In addition, your thoughts and perception cannot be altered by magic (such as modify memory).

Unsullied Mind

At 20th level, your Aura of Mindfulness grants immunity to psychic damage, protects against two types of saving throws, and grants immunity to any effect that would sense emotions or read thoughts, divination spells, and the charmed condition. This aura even foils wish spells and spells or effects of similar power used to affect a protected target’s mind or gain information about the target. Additionally, you gain the ability to communicate telepathically with creatures within 120 feet, even if they do not share a language with you.