Cavalier

Sworn to protect its allies, the Cavalier excels in guarding those they deem important and worthy. Experts in both mounted and non-mounted combat, the cavalier’s unwavering determination focuses on the most dangerous opponent to them and their allies and torments them if they bring harm to those they defend.

Bond of the Saddle

Beginning when you choose this archetype at 3rd level, you learn how to utilise mounts more effectively than others. You have advantage on Animal Handling skill checks on beasts that can be used as a mount. At the DM’s discretion, other creatures that aren’t beasts can also count as mountable beasts for you. You also have advantage on saving throws made to avoid falling off your mount. If you fall off your mount and descend no more than 10 feet, you can land on your feet if you're not incapacitated. Mounting or dismounting a creature costs you only 5 feet of movement, rather than half your speed.
Whenever you spend a short rest with a beast creature that can be mounted, you can form a special bond with that creature, allowing it to become a trusty steed for battle. At the DM’s discretion, you can form this bond with a non-beast creature that can be mounted.
The creature becomes friendly to you and your allies, and you can control it while mounted. If not mounted, the creature acts independently. While bonded, the creature uses its statistics but gains the following benefits:

• Its hit point maximum increases by your fighter level + your Constitution modifier.
• Its armour class increases by your proficiency bonus.
• If the creature is reduced to 0 hit points, it does not die, but instead falls unconscious and makes death saving throws as if it were a player character. The creature follows the same rules as player characters.
• While you mount the creature, you can spend a bonus action to allow your mount to make one melee attack. The mounted creature adds your proficiency bonus to the attack roll. You can only use this bonus action an amount of times equal to your Constitution modifier, and regain all expended uses after completing a long rest.

This bond lasts until you or the bonded creature dies, or you make another bond with a different creature. You can only form this bond with one creature at a time, and can only bond with a creature once per long rest.

Unwavering Mark

Starting at 3rd level, you can menace your foes, foiling their attacks and punishing them for harming others. When you hit a creature with a weapon attack, you can mark the creature for 1 minute. This effect ends early if you are incapacitated, paralysed, stunned, if you die, or if someone else marks the creature with the same feature.
While it is within 10 feet of you, a creature marked by you has disadvantage on any attack roll that doesn't target you.
In addition, if a creature marked by you deals damage to anyone other than you, your next attack that hits the marked creature before the marked creature’s next turn deals additional damage equal to double your Constitution modifier. You can also make one additional weapon attack on your next turn only against a marked creature that dealt the damage to the creature.
You can only have one creature marked by this feature at a time. The maximum number of creatures increases to two at 7th level, three at 15th level, and four at 18th level.

Warding Manoeuvre

Starting at 7th level, whenever a creature marked by your Unwavering Mark damages you or an allied creature within 10ft of you, the targeted creature has resistance to any Bludgeoning, Piercing, or Slashing damage the marked creature does.
In addition, if you’re wielding a shield, allied creatures within 10ft of you also gain the AC bonus granted by the shield.

Ferocious Charger

Starting at 10th level, whenever you or a creature you are mounting uses the Dash action, that creature gains temporary hit points equal to your Proficiency bonus + your Constitution modifier (minimum of 1). On your first turn in combat, you can also use the Dash action as a bonus action.

Retaliating Blow

Starting at 15th level, you can react to your enemies actions and strike back with swift punishment. You can make a special opportunity attack that does not cost a reaction only against a marked target. This special opportunity attack can also be triggered when a marked creature attacks an allied creature other than you. Once you make this special opportunity attack, you cannot do so again until the start of your next turn.
In addition, whenever you use your Second Wind feature while mounting a creature, the beast you are mounting regains the same amount of hit points you regain.

Vigilant Defender

Starting at 18th level, whenever you have a creature marked by your Unwavering Mark, you gain an additional reaction which can only be used for an effect or ability that is triggered by a marked creature or targets a marked creature. This reaction is separate to the special opportunity attack gained at 15th level. Additionally, as a reaction, you can now make opportunity attacks against a marked creature that attacks a creature other than you.