Cadre

Sometimes called "the Emperor's Own", because they serve the Emperor as their direct liege lord.  Upon invitation into the Cadre, you receive superlative training in all aspects of war: tactics, armed and unarmed martial combat, and unequaled biological augmentation in the form of implanted synthetic pharmaceutical organs. Cadre membership is for life--one doesn't retire; you simply go into inactive reserve status, and can be reactivated at any time of the Emperor's choosing.  Cadre members solve only the hardest jobs.  If you are up for the challenge, Cadre status offers the chance to prove you are THE best.

Old Speedy

Beginning when you choose this archetype at 3rd level, part of the biological augmentation you receive during imperial training buys you the most precious combat commodity there is--time.  Old Speedy (a.k.a. "the tick") accelerates your mental processes enormously, and the world around you seems to move in slow-motion, the blink of an eye to others is comparable to 5 seconds to you.  You have all the time in the world to THINK about the possibilities and threats, about actions and reactions, before you actually take them. This enables your perception of other's subtle actions and movement to be alarmingly astute, and your own movement during the tick is metronome smooth and precise, an amalgamation of viperish speed and serenity. 

As a result, you have advantage on all actions, reactions, and saving throws for the duration, which lasts for 3 minutes, available twice per Long Rest.  Because of riding the tick, your weapon attacks score a critical hit on a roll of 19 or 20, or any hit you score against a creature that is surprised.  

The tick ends early if you are knocked unconscious or if your turn ends and you haven’t attacked a hostile creature since your last turn or taken damage since then. You can also end the tick on your turn as a bonus action. 

Due to the highly addictive possibilities of the pharmacopeia pulsing through your system, as a deterrent, the Emperor added a nasty side effect: incapacitating nausea at the end of the tick. You fall prone as enhanced nausea turns your stomach inside out and you vomit for 2 minutes and have disadvantage on all rolls for 5 minutes.

[11th] the tick can keep you fighting despite grievous wounds. If you drop to 0 hit points while you’re riding the tick and don’t die outright, you can make a DC 10 Constitution saving throw. If you succeed, you drop to 1 hit point instead. Each time you use this feature after the first, the DC increases by 5. When you finish a short or long rest, the DC resets to 10.

 [15th] your synthetic organs have optimized so riding the tick ends early only if you fall unconscious or if you choose to end it.

Superior Training

Starting at 7th level, you can add half your proficiency bonus, rounded up, to any ability check you make that doesn’t already include your proficiency bonus.

Your daily training with the tick has paid off.  When an attacker that you can see hits you with an attack, you can use your reaction to halve the attack’s damage against you.

In addition, when you make a running long jump, the distance you can cover increases by a number of feet equal to your Strength modifier.

Additional Fighting Style

At 10th level, you can choose a second option from the Fighting Style class feature.

Archery

You gain a +2 bonus to attack rolls you make with ranged weapons.

Calculated Attack

Beginning at 10th level, your familiarity with the tick has enabled you to strike suddenly and exploit a foe’s distraction. Once per turn, you can deal an extra 5d6 damage to one creature you hit with an attack if you have advantage on the attack roll. The attack must use a finesse or a ranged weapon.

You don’t need advantage on the attack roll if another enemy of the target is within 5 feet of it, that enemy isn’t incapacitated, and you don’t have disadvantage on the attack roll.

The amount of the extra damage increases to 8d6 at 15th level, and to 10d6 at 20th level.

Defense

While you are wearing armor, you gain a +1 bonus to AC.

Dueling

When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.

Great Weapon Fighting

When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.

Protection

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 impose disadvantage on the attack roll. You must be wielding a shield.

Two-Weapon Fighting

When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.

Superior Critical

Starting at 15th level, your weapon attacks score a critical hit on a roll of 18–20.

Inherent Medic

At 18th level, you attain the pinnacle of resilience in battle and have learned to harness your biological augmentation to enhance the healing properties of the pharmacopeia, thus granting you proficiency in all saving throws.

In addition, at the start of each of your turns, you regain hit points equal to 5 + your Constitution modifier if you have no more than half of your hit points left. You don’t gain this benefit if you have 0 hit points.