Eante's Dragoon

The Dragoons are spear-wielding fighters that use their physical strength to add power to their strikes. Although they are capable of taking a hit, their combat style is an offensive and somewhat riskier one compared to most other options in the fighter sub-class list. Positioning, movement management, and usage of the battlefield conformation are crucial skills for any player interested in playing this sub-class.

Flavor-wise, Dragoons typically belong to guilds or organization that focus their activity around the extermination of dangerous beasts and creatures although is not unheard of for a dragoon to fly solo.

Airborne Meaneuvers

Powerfull legs: 

Dragoons maximum high jump distance is equal to one half their movement speed+strenght modifier (rounded down) and their maximum leap (long jump) distance is equal to their movement speed+strenght modifier (rounded down). Dragoons take no fall damage if the height they fell from was less than his movement speed, they take half the normal amount of damage in any other case). 

Airborne Maneuvers: once a turn you can use on the Dragoons airborne maneuvers. Dragoons learn Collision at level 3, SKydive at level 5 and Horde breaker at level 8.

Collision: dragoons who moved at least 15 feet in a straight line towards an enemy can perform a leap (long jump, minimum distance to perform it 10 feet) to collide with said enemy. On a hit, collision deals: standard attack damages (spear die+modifier) + 1d4 bludgeoning damages for every 10 feet spent running towards the target enemy + 1d4 bludgeoning damages for every 10 feet spent leaping towards the target enemy. The maximum distance covered with Collision is equal to (2*movement speed) + strength modifier. Collision is considered a full action and no extra attacks (unless coming from a bonus action) can be made the turn this is used.

Skydive: dragoons can jump onto a target from a higher ground position dealing: standard attack damages (spear die+modifier) + 1d6 bludgeoning damages for every 10 feet of initial height*. For the purpose of damages calculation jumping from 10 or 19 feet makes no difference. Upon landing a critical hit on a target after jumping from a height of 20 plus feet Skydive forces the receiver of the attack to make a strength saving throw. On a fail, the target is: stunned for one turn if it's one size smaller than the dragoon, it's pinned to the ground (works like grappled) and unable to take reactions if of the same size as the dragoon, and it falls prone if of the same size as the dragoon. Creature more than one size larger than the dragoon do not suffer any additional effect from Skydive.

Horde Breaker: As Dragoons hone their skills and strengthen their bond with the dragon spear, at level 7, they are now able to impact more enemies with jump attacks if they so choose. Skydive can now spread damages across enemies in a five feet of radius area while Collision can spread damages in a cone (15% angle). Damage depend on number of enemies: 2 enemies (each get 75% of the normal damage of the attack, rounded down), 3-5 enemies (each get 50% of the normal damage of the attack, rounded down), 5+ (each enemy gets 25% of the normal damage of the attack, rounded down).

Dragon's Tail

At level 7, Dragoons are able to bond with their spear by performing a one-hour bonding ritual. The bonded weapon takes the name of Dragon's tail and it's considered magical for the purpose of overcoming immunities to non-magical attacks. 

Dragoons attacking with their Dragon's Tail do not suffer disadvantage when attacking with it in melee range.

Dragoons can, as a bonus action, cause their Dragon's tail to appear in one of their free hands (summoning it with a command word to be decided during the ritual) or make it disappear.

True hunter's trophies

At level 10, Dragoons learn how to draw strength from scales of dragons and dragon-like creatures ( example, weaverns). After killing (dealing the final blow) a dragon or a dragon-like creature (ask the DM to compile a list) they can harvest some of its scales necessary to perform the consumption ritual, transferring a small fraction of the dragon might and soul into their own bodies. Based on how many rituals Dragoons performed with scales from different and unique dragons or dragon-like creatures (example: killing two weaverns and using their scales would not set the counter to two but leave it at one as it's just one type of dragon-like creature) they get the following bonuses below.

0. At level 10, before the first ritual, dragoons develop some sort of sixth sense that "warns" them when they find themselves anywhere near creatures like the ones they crave to hunt.

1. Dragoons muscle fibers grow in number and elasticity, their movement speed is increased by 10 feet.

3. Dragoons know what withstanding a breath attack from a dragon looks like. When on the receiving end of an elemental attack (everything except force, radiant, necrotic, psychic, whatever else I forgot) they can absorb part of the damage as reaction (aka you gain resistance to said element for that attack). On their next attack, they add 2d4 of that type of elemental damage to their damage calculation. They can use this feat a number of times equal to 1 + Wisdom modifier.

5. Dodging, ducking and trying to avoid the attacks of the mighty creatures Dragoons hunt makes them particularly agile and adept at taking care of themselves in a fight. AC+1.

7. Bathing in the blood of a dragon is an exhilarating experience for Dragoons in the middle of their battle frenzy. Dragoon's body starts developing somewhat draconic traits. Three times per long rest they can sprout a set of wings off their backs. Each use can not last longer than 30 minutes and their flying speed is equal to their walking speed.

10. Reaching this point Dragoons becomes the true embodiment of the hunt and are able to further enhance their physical abilities when in combat. Once a day, as a bonus action, Dragoons can enter their battle frenzied for which grants them +2 to strength (allowing the dragoon to reach strength levels above 20), +10 feet to their movement speed and the ability to add their proficiency bonus to the length of their leaps and the height of their jumps and offering them resistance to one type of physical damage. Battle frenzy lasts for 1 minute (10 turns).

Thrill of the hunt

At level 15, once a day, if Dragoons are reduced to 0 hit point while facing a single enemy, they can instead resist with one HP. They can then immediately perform one attack action (not one attack, one attack action) regardless of turn order. At the end of said action if the creature who reduced them to 1 HP has action/attacks/bonus action or movement to spend it will have faculty to do so.

Impale

At level 18, once a day,  Dragoons' mastery of the spear and battle forged bodies, allow them to perform the Impale maneuver. If Skydiving from 100+ feet of height or using Collision from more than 110 feet of distance (55 movement+55 leap) Dragoons can decide to trigger Impale. They can roll with advantage to see if the attack lands. On a hit the creature receiving the damages is reduced to 0 hit points unless it has resistance or immunity bludgeoning damages in which case it suffers 100 damages. In any case, if the attack lands the dragoon will be left with one hit point and two points of exhaustion. If the attack misses the dragoon takes damages based on the fall and one point of exhaustion.