Martial Archetype
Comments from the Finger: Tome of Battle, Book of the Nine Swords was a 3.5 book regarded today with mixed opinions. It introduced three base classes to the edition, which thematically were replacements for three mechanically weakest martial classes of the edition. Swordsage replaced monk, Warblade replaced Fighter, and Crusader replaced the paladin. Mechanically, these classes used a system of maneuvers which functioned similarly to spells and allowed to classes to walk in lockstep with the high powered casters of that edition. Today, the Warblade and the maneuver system has been inherited in the Battle Master fighter subclass, and we’ve done our own version of the Swordsage.
Perhaps the design decisions to omit the maneuver system from this subclass and make it a fighter subclass will be controversial ones, but they allowed me to focus on the interesting mechanic of the delayed damage pool and simply being tough to kill. Otherwise, this class might have primarily focused on channel divinity at lower levels, or had too many features and too much power. As it stands, this class represents a defensive, tanking fighter, much like the Warden of 4e.
Crusader
Fully clad in shining armor, the Crusader is a wall of steel, the tank of a medieval battlefield. Whether drawing his blade against man or monster, the Crusader strikes true, and always lives to tell the tale.
Steely Resolve
Beginning when you choose this archetype at 3rd level, you have a pool of delayed damage that allows you to forestall the effects of your injuries. When you take damage, this damage is added to your delayed damage pool, instead of being subtracted from your hit points. At the end of your turn, you take damage equal to the total stored in your delayed damage pool, which then resets to 0.
When you restore hit points, you choose whether it reduces your damage pool, your restores your hit points normally, or both (you can split the amount of healing as you wish).
At 3rd level, your delayed damage pool can hold up to 5 points of damage. Any damage beyond that comes off your hit points as normal. The maximum damage your pool holds increases by 5 at 6th (10 points), 9th (15 points), 12th (20 points), 15th (25 points), and 18th (30 points.)
Furious Counterattack
At 3rd level, you gain a bonus to damage on melee attacks equal to your delayed damage pool divided by 5, rounded down.
Damage Flush
Beginning at 7th level, you can, as a bonus action in your turn, reduce your delayed damage pool to zero without decreasing your current hit points. After using this ability, you must complete a short or long rest before using it again.
Die Hard
By 7th level, it is exceptionally hard to kill you. You no longer suffer instant death from taking damage exceeding your hit point maximum. In addition, instead of falling unconscious when you are reduced to 0 hit points, you are instead incapacitated and prone. Death and death saving throws otherwise function as normal.
Impose
Starting at 10th level, when a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to change the target of that attack to yourself. This attack has advantage against you.
Indomitable Soul
At 15th level, you gain advantage on an Intelligence, Wisdom, or Charisma saving throw. After using this ability, you must complete a short or long rest before using it again.
Additionally, you have advantage on saving throws against being charmed or frightened.
Improved Damage Flush
Beginning at 18th level, you can use Damage Flush a number of times equal to your Constitution modifier. When you do so, you can also end either one disease or one condition afflicting you. The condition can be blinded, deafened, paralyzed, or poisoned. You regain all expended uses when you complete a long rest, or 1 use when you complete a short rest.
Changelog: 8/3/15: Damage Flush now also ends one condition.
8/4/15: Features rearranged. Die Hard is now 7th, Damage Flush is now 7th and no longer ends conditions, Impose is 10th, Indominable Soul is 15th, Improved Damage Flush is at 18th level and ends one condition and changes use of Damage Flush to Con/long.