The Paladin

Clad in plate armor that gleams in the sunlight despite the dust and grime of long travel, a human lays down her sword and shield and places her hands on a mortally wounded man. Divine radiance shines from her hands, the man’s wounds knit closed, and his eyes open wide with amazement.
A dwarf crouches behind an outcrop, his black cloak making him nearly invisible in the night, and watches an orc war band celebrating its recent victory. Silently, he stalks into their midst and whispers an oath, and two orcs are dead before they even realize he is there.
Silver hair shining in a shaft of light that seems to illuminate only him, an elf laughs with exultation. His spear flashes like his eyes as he jabs again and again at a twisted giant, until at last his light overcomes its hideous darkness.
Whatever their origin and their mission, paladins are united by their oaths to stand against the forces of evil. Whether sworn before a god’s altar and the witness of a priest, in a sacred glade before nature spirits and fey beings, or in a moment of desperation and grief with the dead as the only witness, a paladin’s oath is a powerful bond. It is a source of power that turns a devout warrior into a blessed champion.

In The Nameless Trilogy World

The noblest and the bravest of warriors, who struggle on behalf of oaths that are far greater than those given to kings and queens, the paladin stands tall amidst the classes. Their stature and demeanor alone attracts attention and respect as they walk through the city streets, clad in armor, bearing sword and shield. Their life can sometimes be seen as a lonely one, for who can stand alongside them when all evil and darkness is breaching upon the shores. 
The militaries of many nations employ paladins for their strength and fortitude on the battlefield, and for their respectful charisma among the citizenry. Paladins usually find themselves on the fast track to becoming officers and captains, with soldiers and squires serving under them. Many famous heroes of our day began as paladins, studying the sword or other weapons, following divinely-inspired oaths, and never faltering on the battlefield. 
Meanwhile, other paladins train specifically to confront the wilderness and the monsters therein, standing alone upon the frontiers of this world and fighting darkness wherever it is found. Sometimes they will find a single village upon a long forgotten road and choose to stay, if only to protect the few hundred people who live here outside of the shelter of the great nations.

Resources:

• Player's Handbook
• Xanathar's Guide to Everything
• Xanathar's Lost Notes to Everything Else
• Sword Coast Adventurer's Guide

Subclasses:

• Oath of Devotion (PHB)
• Oath of the Ancients (PHB)
• Oath of Vengeance (PHB)
• Oath of Conquest (XGtE)
• Oath of Redemption (XGtE)
• Oath of Predation (XLNtEE)
• Oath of Providence (XLNtEE)
• Oath of the Crown (SCAG)