This subclass is designed to give a reasonable buff at the monk at low levels, due to the increased ki points and the option of use Wisdom for attack rolls; and at higher level to make a competitive martial class in an overwhelming magic world like the forgotten realms. The lore of the tiny acorn is related to my homebrew setting, but does not affect the subclass features at all.

You will focus your training in channeling the power of the Ancient Oak of the great temple of Rithfold, which can negate the magic around itself due to a mistical connection to the Weave.

Superior Mind

Starting from when you choose this monastic tradition at 3rd level, the training of the Temple of the tiny acorn gives you mental and sensorial capability to improve your performance in and outside the fight. You gain proficiency in Arcana and Religion checks, if you haven't already.

You can now use your Wisdom modifier instead of Dexterity or Strenght, for attack rolls and damage of your unarmed strikes and your monk weapons.

The maximum ki point you can have is now equal to your level plus your Wisdom modifier.

In addition, you can expend 1 ki point to cast Detect Magic, without the need of any component.

Mistical Consciousness

At 3rd level, you have reached a mistical connection to the world surroundings . You gain a bonus to Initiative check equal to your Wisdom modifier. In addition, you can expend 1 ki point to gain advantage to that roll.

Magic Refractory

At 6th level, when you are hit by a spell or a magic weapon, assumed that the damage is dealt by an attack roll, you can expend 1 ki point to reduce the damage by 1d10 + your Wisdom modifier + your Monk Level.

You can use this feature also when another creature, within 5 ft of you, takes damage from a spell or a magic weapon, through an attack roll.

In addition, when you make a Wisdom, Intelligence, Carisma saving throw you can add your Wisdom modifier to the roll (minimum +1).

Magic Suppression

At 6th level, your ability of anti-magic control is incomparable. Expending 3 ki points, you can cast one of these spell as you cast them with a 3rd level slot, without need of material components:

Counterspell, Dispel Magic, Nondetection.

You can cast these spells at 4th level or higher expending one additional ki point for each additional spell level. Your spellcasting charateristic for these spell is Wisdom. The maximum ki points you can expend (base spell cost included) to cast these spells is equal to half your Monk level (rounded up). Maximum of 9 ki points at 19th and 20th monk level

Reflective Strike

At 11th level you can harness and reflect the magic energy of a spell. When you are targeted by a spell and that spell miss the attack roll or you success the saving throw, you can expend a number of ki points equal to the spell level to reflect it to the caster. You need only somatic components to do so and you have to make an attack roll if needed or the target must succeed your spell saving DC. 

Anti-Magic Field

At 17th level, you can negate the presence of magic around yourself. Expending 9 ki points you can castAntimagic Field, with only somatic components needed. You still have to concentrate on the spell for the full duration.

If you expend an additional ki point when casting this spell, you can double the area of effect of the field.