I personaly have never played with the Monk class but what I really like to do is to create level 20 monks at one point Monks are to weak but then a couple levels later they are very OP Deflect missles lvl 20 is 1d10 + 25 damage reduced but then at other points like at level 1 the monks are so weak. One more thing about level 20 is slowfall - 100 ??? And finnaly this is something that I myself do not feel strongly about is Wholeness of body but I know that some people feel strongly.

I have played a monk through ot level 20 (and with quite a few epic levels). Only one character (open hand) but here is my experience of your suggestions and what I think is most powerful.

Your suggestions

• Slowfall: Useful but not huge. Some characters can fly or glide to avoid damage, feather fall is a first level spell. Theoretically you can prevent 100 damage but maximum fall damage is 20d6 which averages 70 and most of the time you are only falling maybe 50-60 feet.
• Deflect missiles: I only it come up a couple of times. Most monsters have melee attacks, cast spells or have other ranged attacks (e.g. dragon breath). Not sure what has a 1d10+25 ranged attack but evasion will reduce the damage from an anciant dragons fire breath by an average of 45 and a meteor swarm damage by an average of 70. (and Evasion didn't make my top 3)
• Wholeness of body: Useful bit of healing but it takes up an action so you want to avoid it in combat if you can especially as if prevents attacking with your bonus action.  If you have two combats without a rest between is the best time ot use it.  Note that this is only available ot open hand monks

My picks (in order of level received)

• Stunning strike. Con is a common save but at high levels you can throwing these out until you succeed. A boss doesn't want to be stunned so it is a great way of burning through legendary resistances otherwise they do nothing for the round while everyone hits them with advantage
• Diamond Soul: At higher levels saves are far more important for defence than AC. Having proficiency in all saving throws is fantastic.
• Empty Body: Uses 4 ki but you are invisible so all your attacks are at advantage and attacks against you are at disadvantage (RAW even if the enemy has truesight. blindsight or similar) and you are resistant to virtually all damage.

Quote from Jegpeg >>

I have played a monk through ot level 20 (and with quite a few epic levels). Only one character (open hand) but here is my experience of your suggestions and what I think is most powerful.

Your suggestions

• Slowfall: Useful but not huge. Some characters can fly or glide to avoid damage, feather fall is a first level spell.
• Deflect missiles: I only it come up a couple of times. Most monsters have melee attacks, cast spells or have other ranged attacks (e.g. dragon breath)
• Wholeness of body: Useful bit of healing but it takes up an action so you want to avoid it in combat if you can especially as if prevents attacking with your bonus action.  If you have two combats without a rest between is the best time ot use it.  Note that this is only available ot open hand monks

My favorites (in order of level received)

• Stunning strike. Con is a common save but at high levels you can throwing these out until you succeed. A boss doesn't want to be stunned so it is a great way of burning through legendary resistances otherwise they do nothing for the round while everyone hits them with advantage
• Diamond Soul: At higher levels saves are far more important for defence than AC. Having proficiency in all saving throws is fantastic.
• Empty Body: Uses 4 ki but you are invisible so all your attacks are at advantage and attacks against you are at disadvantage (RAW even if the enemy has truesight. blindsight or similar) and you are resistant to virtually all damage.

 

 Thanks for the great suggestions I will remember these if I ever have a level 20 Monk :D