Enhanced Senses

At 3rd LVL your monk goes blind for some reason you can incorporate it in his backstory or maybe he faced a gruesome injury at LVL 2 or in some rare cases monks choose the way of the blind monk and blind themselves to be able to enhance their senses. 

Being Blind Your other senses become enhanced and while all individually are weak with all 4 of your now enhanced senses you can see pretty well.

Smell

You gain the ability to smell as a bonus action. when you smell like this you take a deep breath in and can smell any creature within 60 ft. This does not give you an exact location instead you would be able to point in the direction of the creature. also if you are familiar with the smell of this creature you can identify what kind of creature it is. to do this you must have encountered this creature since you went blind ( keep a lsit of the creatures you encounter in your adventure if you want to play this fair.
Touch

You become sensitive to the vibrations in the ground around you. You gain tremorsense sense of 30 ft and are able to see through walls. Creatures must be touching the ground you are standing on to be able to see them so you are blind to flying or incorporeal creatures with tremorsense. You can also make a (DC 15) perception check to see what's inside a solid object such as a key encased in stone or a person buried underground.

Taste

As an Unarmed strike, you can forgo your damage to lick an enemy. if you make this kind of unarmed strike and lick a creature you can learn information about its capabilities compared to your own: Strength score, Dexterity score, Constitution score, Armor Class, current HP, total class levels (if any), monk class levels (if any)

Starting at 3rd level, if you lick a creature as an unarmed strike, the strike does no damage but you can learn certain information about the creature's capabilities compared to your own. The DM tells you if the creature is your equal, superior, or inferior in regard to one of the following characteristics of your choice:

Greater enhanced senses

Smell

your smell range increases to 120 ft.  As your senses grow sharper you begin to notice that not only do different creatures have different smells but individual people have their own unique smell. now you can identify familiar people by their unique smell. If they are a "close friend" you can smell them from 240ft. someone is considered a close friend when you have traveled with them for a week or longer.

Touch

Your blindsight of tremorsense increases up to 60 ft. and you become proficient in insight becoming able to feel people's heartbeats through their bodies.

Hearing

Your blindsight extends to 30 ft as you become more adept at echolocating you also get to add your wisdom modifier to your initiative becoming more familiar with what sounds around you may be a threat or not. 

Taste

Your Lick feature now reveals two characteristics.

Starting at 3rd level, if you lick a creature as an unarmed strike, the strike does no damage but you can learn certain information about the creature's capabilities compared to your own. The DM tells you if the creature is your equal, superior, or inferior in regard to TWO of the following characteristics of your choice:

Curse of the Blind Monk

You can spend an attack action and spend a ki point to stare at a single creature through your blind eyes to cause them to make a wisdom saving throw on fail cause blindness in them. this blindness remains as long as you can maintain eye contact with them. you cannot use your blindsight or tremorsense for this eye contact it is if you can see their eyes with your eyes. and if you are hit while maintaining this blindness you are forced to make a concentration saving throw like regular concentration magic. If you can maintain this blindness for 1 minute (10 turns) the creature is permanently blinded.

 

Gift of the Blind Monk

With your familiarity with the energy of blindness and your closeness to the meaning of blindness, you become able to spend 6 ki points and cure blindness in any creature.

Greater Curse of the Blind Monk

When using Curse of the Blind Monk you still need to take one action per creature you try to blind and make eye contact when you cast it, but after you cast all you need to do is maintain concentration and are able to cast it on again on another creature while maintaining concentration on the first creature. You are able to Maintain concentration like this for up to 4 creatures at once.

Perfect Enhanced senses

Smell

you can smell more specific details such as if the creature is bloodied from having recently fought and what kind of armor they are wearing.

Touch

You gain expertise in insight 

Hearing

you can't be surprised at all unless deafened or otherwise silenced enemies.

Taste

you can gein 4 of the characteristics from your lick feature