• Callidus – Chameleons able to infiltrate anywhere and impersonate anyone.
• Venenum – Elite poisoners able to craft deadly concoctions from virtually anything, equipped with the deadliest toxins from across the universe.
• Vindicare – Marksmen of unparalleled skill equipped with the Imperium’s most lethal weaponry.
• Sneak Attack (d4s) and Extra Attack
  Unlike normal rogues, when you choose this archetype your sneak attack die decreases to 1d4. Also unlike normal rogues, at 5th level you gain Extra Attack (able to attack twice when you take the attack action).

Level 3: Assassinorum Apprentice

Assassinorum Apprentice
Starting when you choose this archetype at 3rd level, you are drafted into one of the mysterious organizations of the Assassinorum, the clades of assassins that work in the Imperium of Mankind’s shadows. Choose one of the temples described above (Callidus, Culexus, Eversor, Vanus, Venenum, or Vindicare). You gain different archetype features depending on which clade of the Assassinorum to which you belong.

Callidus: Impersonatio

You gain proficiency with the disguise kit. You have advantage on checks made to maintain a disguise, including Charisma (Deception) checks and the use of tool kits (although it should be noted that you do not have advantage on checks to actually use a tool kit, just to make it appear as though you are proficient and that you know what you are doing).

Venenum: Amateur Poisoner

You gain proficiency with the poisoner’s kit, resistance to poison damage, and advantage on saving throws against poison.

Vindicare: Marskmanship

You do not have an off-hand (each of your hands counts as your primary hand). In addition, you are gifted with an Executor sniper rifle (2d10 piercing, range 500/5,000, weight 20 lbs., reload [8 shots]).

Level 9: Assassinorum Rank

Beginning at 9th level, you become a proper agent of the Assassinorum and receive a powerful gift with which you can better see to the God-Emperor’s will.

Callidus: Polymorphine Amateur

The Callidus Temple supplies you with polymorphine, a chemical substance that drastically alters your physical makeup for a number of hours equal to your proficiency bonus. You are able to cast alter self at will with no components other than polymorphine. In addition, you may spend a bonus action to gain one of the following benefits while using polymorphine. Switching from one benefit to another is a bonus action or reaction.

Venenum: Toxica Tools

Your masters have given you toxica tools, items perfectly suited to be used as a miniature chemistry set with one purpose–the crafting of poisons. You have advantage on checks made to hide your toxica tools on your person and gain a +5 bonus on Dexterity (Sleight of Hand) checks to do so. With 10 minutes of work, you can craft a number of poison dice equal to your level + Intelligence modifier. These poison dice are d8s. You may choose to craft all of your poison into one deadly toxin that deals a maximum amount of d8s equal to your rogue level, or in several smaller vials. Any living creature that ingests or is struck by your poison takes the poison dice as additional poison damage to the attack, making a Constitution saving throw (DC 8 + your proficiency bonus + your Intelligence modifier) for half damage. After 24 hours, any poisons made this way go inert. Once you have used this feature to brew poison, you cannot do so again until you have finished a long rest.
In addition, you can spend a bonus action to poison a melee weapon or piece of ranged ammunition.

Vindicare: Optical Implant

The Vindicare Temple replaces one of your eyes with an enhanced cybernetic. You gain darkvision 200 feet, you do not suffer disadvantage on ranged weapon attacks from being within an enemy’s reach, and you always know the exact distance between your cybernetic eye and any object it can see.

 

Level 13: Assassinorum Veteran

Starting at 13th level, you have successfully completed enough missions for your clade that they reveal more of their hallowed trade secrets.

Callidus: Polymorphine User

While using polymorphine, you gain two benefits instead of one, you do not require concentration to maintain your alter self, and the duration of polymorphine doubles.

Venenum: Poisonous

You gain immunity to poison and the poisoned condition. When a living creature deals damage to you with a bite attack, it takes 1d4 poison damage per point of proficiency bonus you possess.

Vindicare: Gunslinger’s Reaction

On a surprise round (even when you are surprised), you can draw your weapon(s), make a single ranged weapon attack (or two if wielding two ranged weapons), and move up to half your movement.

Level 17: Assassinorum Elite

When you reach 17th level, you are one of the Imperium of Mankind’s foremost stealth agents, able to infiltrate virtually anywhere in the universe to kill your target (and possibly even escape afterward).

Callidus: Polymorphine Expert

While using polymorphine, you gain four benefits instead of two, its duration doubles again, and your alter self remains active even when you are unconscious, suspending the polymorphine’s duration until you regain consciousness.

Venenum: Poisona Fatalis

By spending 1 hour brewing, you can use a poisoner’s kit and your toxica tools to craft a fatal poison. Any living creature that ingests or is struck by your poison makes a Constitution saving throw (DC 8 + your proficiency bonus + your Intelligence modifier) or takes 10d6+40 poison damage. If you have detailed knowledge and a sample of a living creature’s blood, you can spend an additional hour tailoring the toxin to specifically target that creature, causing it to have disadvantage on its saving throw.

Vindicare: Deadly Shot

When you spend a bonus action aiming with a ranged weapon attack and hit the target you were aiming at with your next attack roll, as long as you hit it is automatically a critical hit