You have served in the dwarf legions and know how to fight to survive.
Requirement: Dwarf.
Features
Level 1: Dwarven Toughness. Your hit point maximum increases by 1, and another 1 each time you gain a level.
Level 1: Darkvision. You have darkvision out to 120 feet.
Level 4: Hardy. You have advantage on Strength and Constitution saving throws.
Level 10: Formation Fighting. You gain a +1 bonus to AC, or a +2 bonus while wielding a shield.
Level 19: Disciplined Reprisal. When a creature within 5 feet of you attacks you or an ally within 5 feet, as a reaction you can make a melee attack against the creature.