Nukenin (Rogue Ninja)

Nukenin are ninjas with no masters, Rogues that focus on combat rather than thievery, with extremely powerful burst mobility options they can chase down any target and use combat focus techniques, unlike normal rogues howhever,  running away is not an option, they are aggressive assassins who will get to their target no matter what is in their way, using their abilities to run away is not an option

as a Nukenin you'll gain powerful movement and combat abilities using "Ninpo Counters" alongside some generally useful less powerful passives that help achieve the same goal of relentlessly hunting down elusive targets, high risk and high reward.

Ansatsu

Starting at 3rd Level, you gain acess to the forbidden Ninja Arts of assassination

if Unarmored or wearing Light Armor, your movement is increased by 20/40/60/80 at levels 3. 7, 9 and 17 while moving towards an enemy, if moving away from an enemy and towards no other enemies you take a 10ft movement penalty instead as cowardice is unnaceptable in your mission.

you also gain acess to Ninpo Points that can be used to perform one of the 3 following Ninja Arts:

- Ninja Art: Alpha Blade - by using 2 Ninpo Points, using yout attack action for this turn, when you attack with a finesse weapon you can teleport through enemy creatures in a straight line diagonally, horizontally or vertically up to the end of your movement, rolling a single attack roll against all their ACs and applying the same damage to all of them, if there are no targets for this attack, it has no effect

- Ninja Art: Fuuma Shuriken - Passively Your Small Throwing Knives become Shuriken (dealing 1d6 slashing damage, Finesse, Light, Thrown (range 40/200), Special), using 1 Ninpo Point when a shuriken hits an enemy, you instantly teleport to an adjacent space in the place of your shuriken and can perform an extra attack as a bonus action.

-Ninja Art: Izuna Drop: Using 2 of the Ninpo points, You teleport to an airborne creature you can see and perform a grapple attempt, on a success you both spin in the air crashing to the ground, the target takes double fall damage as you use its body to cushion your own fall making you take half fall damage on a failed dex save and no damage on a successful one

You get 3 ninpo points at level 3 and one more every 2 levels, Ninpo points reset after a Short or Long Rest.

Shadow Onslaught

Starting at 3rd Level, you can spend up to 20% of your life energy to create shadow copies of yourself, by paying 20% of your max hp the Nukenin creates 1d2+1 copies of himself  who share his stats, attacks, weapons and reactions, but only 20% of the nukenin's max hp
they get their turn right after the Nukenin but their attacks deal halved damage.

Nukenin and the clones get advantage on their attacks if they are within 5ft of another clone or the creator of the clones, and enemies attacking them have disadvantage under these conditions

the clones last for 1 minute in combat but if not in combat they can last for up to 1 hour, if their hps hit 0 they disappear into a cloud of smoke

Once you use this feature, you must finish a short or Long Rest before you can use it again. Starting at 17th level, you can use it twice before a rest, but only once on the same turn.

Sigma Blade

At 9th level, your precision becomes unmatched and you are able to find weaknesses in the toughest opponents, no armor is safe against you

by spending 3 ninpo points you enter an hyperfocused state of mind for 1 minute, causing you to critically strike at 1 number lower than usual (if 20, becomes 19, if 19 becomes 18, and so on.) when using finesse weapons.

this effect can bypass adamantium armor's critical strike immunities.

Ninpo Element

at 13th Level you learn to channel the element of your life force into your combat, you can roll a d6 to determine what element your energy resonates with and gain an ability depending on each element

1 Katon (Fire) : You gain a free cast of the Fireball spell each day and your fire damage cannot be resisted

2 Suiton (Water) : You create a serpent-like water dragon who is 10 ft wide and 50 ft long and launch it on a straight line, creatures in it's path will need to take a dex save (DC equals 15+Wis modifier) on a failed save they take 10d10 force damage, half as much on a succesful one and be dragged away with the dragon unless you succeed a STR save with the same DC. if the water dragon launches you against a solid surface you take an extra 5d10 bludgeoning damage , this can only be used once per day

3 Doton (Earth): You create a Rocky dome with a 20ft radius and trap creatures inside of it, you can either lock the dome suffocating the creatures inside if they can't find a way out within 1 minute or create small openings refreshing this timer to fill the dome with something. the dome has HP equal to 50+WISx10 and resists slashing and piercing damage

4 Raiton (Lightning): You can spend your bonus action to coat a Finesse weapon in Lightning adding 2d6+WIS lightning damage for 10 minutes to your attacks with that weapon, also when using the Alpha Blade ninpo with a weapon coated by this feature the attacks becomes "Lightning Blade" and will leave enemies who fail a DC15+WIS saving throw stunned for 1 minute, repeating the save at the end of each of their turns to end it earlier

5 Fuuton (Wind) - Your shuriken become magical slashing and gain 1d6 force damage as a bonus, you can spend a ninpo point to increase that force damage bonus to 3d6 coating the shuriken in wind making it 5 ft wide, and able to hit multiple enemies on a straight line

6 Endon (Inferno Style) - You spend an action to target one creature you can see and coat it in black flames who cannot be resisted and ignore fire immunity, they take 2d6+WIS damage at the start of each of their turns and the damage only stops if you choose to deactivate it or gets knocked unconscious.

while you have this flame on a target you are blinded in one of your eyes giving you disadvantage in your attack rolls and if you keep it on a creature for more than 30 seconds you roll a 1d2 every turn, on a 1 you get blinded permanently and the blindness cannot be undone by anything short of a Wish spell.

you can try to reroll your element every 5 days up to a maximum of 3 rerolls

Death Mark

at 17th Level as a bonus action, teleport behind a creature inside your movement range and marks it with your death mark which will explode at the end of it's next turn. then teleport back to your original position

when the death mark explodes it will deal half the total damage you've dealt to it in the turn the death mark was placed 

if a creature dies through the Death Mark's explosion you recover 3 ninpo points and can use this ability again, if not you can only use it after a long rest