Shinobi

Shinobi are those who have specialized in the ancient arts of assassination, poison, deception, and acrobatics to enhance their killing potential to new heights. Specializing in a fluid and flexible combat style that emphasizes misdirection followed by devastating force, a shinobi can slaughter groups of enemies before quietly retreating into the shadows before anyone knows what happened.

Rasetsu

At 3rd level, you have to siphon the vitality of your foes to augment your body. Every time you deal damage with your sneak attack with a melee weapon or unarmed strike, you gain double the damage dealt by the sneak attack as temp hp. While you have temporary hit points, you don’t trigger attacks of opportunity by your movement, have advantage on stealth checks and attack rolls. These temporary hit points last for one hour.

You also gain proficiency in scimitars, longbows, blowguns, sickles, and scythes.

Intonjutsu

At 3rd level, you have learned to conceal your presence using smoke bombs. As a bonus action, you can drop a smoke bomb at your location or a location within 30 feet of you. A cloud of thick smoke pours out in a 10-foot radius from the bomb. The cloud's area is heavily obscured to all creatures but you. The smoke cloud lasts for one round. 

You can have a number of smoke bombs on your person equal to your proficiency bonus. When you complete a short rest, you may create a new set of smoke bombs.

You can also conjure shuriken or kunai to strike at your foes. As a bonus action, you can manifest a single magical kunai or shuriken (using the stats of a dagger) and immediately hurl them, making a ranged or melee attack. A kunai or shuriken vanishes if you don't hurl it or strike with it right away, and they disappear right after they hit or miss. You have advantage on attack rolls against any creature hit by a kunai or a shuriken until the start of your next turn. However, attacks with kunai and shuriken cannot benefit from sneak attack.

 You also gain proficiency with the herbalist's and poisoner's kit.

Minamo Hokō

At the 9th level, you have mastered the art of traversing any surface. You gain a climbing speed equal to your walking speed. You can move up, down, and across vertical surfaces and upside down along ceilings while leaving your hands free. You can stand on and move across any liquid surface as if it were solid ground. While you have temporary hit points, your speed increases by 15 feet.

Ninpo

At 13th level, you have special shinobi arts for confusing, evading, and crippling your foes. You gain the following abilities.

• Enhanced Smoke Bomb: Your smoke bomb now has a radius of 30 feet and a range of 60 feet. Friendly creatures no longer have their vision obscured your smoke bomb.
• Shinobi Toxin: You can change your sneak attack damage to magical poison damage. While you have temporary hit points, you may change the entire attack’s damage to magical poison damage.
• Shinobi-aruki: Your long jump and high jump distance are tripled, and you may use dexterity rather than strength to calculate your long and high jump distance. Lastly, you may choose to engage in a long jump or high jump when you disengage or dash.
• Enhanced Arsenal: You gain a bonus to hit and damage rolls with your kunai and shuriken from your Intonjutsu feature equal to half your proficiency bonus rounded down.

Master Shinobi

At 17th level, you have mastered the shinobi arts and honed them to perfection. Your Ratestu now grants temporary hit points equal to triple the damage of your Sneak Attack. If the target either cannot see you or is unaware of your presence, you may make a free kunai or shuriken attack whenever you make a weapon attack. This ability cannot trigger itself.

Your kunai and shuriken now mark creatures struck by them. The mark lasts for one round. Whenever a friendly creature hits a marked creature, that creature takes magical poison damage equal to a roll of your sneak attack and the mark is consumed.