This is just a cool subclass.

 

Ninja Arts

Starting when you choose this tradition at 3rd lvl, you can use your Ki to duplicate the effects of certain spells. You can spend 2 Ki points as an action to cast darkvision, pass without trace or silence without providing material components or as a bonus to cast zephyr strike.  Aditionally you gayin the minor illusion and control flames cantrips, if you don't already have them

Infiltration Training

Also at 3rd lvl, you learn various infiltration techniques. You gain proficiency with thieves' tools and you may sped a Ki point as action to cast disguise self.

Deadly Strike

Beginning at 6th lvl, your training has taught you how to strike hard at weak spots. Whenever spending a Ki point, you may add one d4 to your deadly strike dice pool. This pool resets after a short or long rest. When you hit a creature with an unarmed strike or monk weapon you may expend any number of dice from your deadly strike dice pool and roll them to deal force damage to the target equal to the amout rolled, in addition to the attacks damage.

Smoke And Mirrors

Starting at 11th lvl, you can throw a smoke bomb as an action to a point within 30' that creates a smoke cloud with a 20' radius. In this radius vision is heavily obscured and the smoke lasts for 1 minute before disapearing. As a part of this action, if you are withing the radius, you may cast greater invisibility or dimension door. You can also use you reaction to allow any allies in the affected area to move up to a higher movement speed. You can use this ability a number equal to half of your wisdom modifier (minimum of once) and you regain all expended uses when you finish a long rest. Aditionally, you may now spend 2 Ki points as an action to cast mirror image.

Strike To Kill

At 17th lvl you have mastered the ability to strike when your enemy is weak. You can acitvate this ability at the beginning of a fight and in that fight, any hit you get on a restrained, stunned or unconscious target is now a critical hit. One use that is replenished after a long rest.