Way of the Waxing Moon (5e)

Drawing from nature, monks of the Waxing Moon take inspiration from the connection druids form with the world around them. These monks exhibit shape-shifting abilities inspired by the druid’s ability to take on the shapes of nature’s beasts.

Flexible Form
At 3rd level, your unique usage of your ki grants you an unnatural level of control over your body. You gain the following features.
 * You can manipulate the proportions of your limbs in short bursts. When you make an attack roll or use a feature that requires a ki point to be spent, you gain 5 feet of reach until the start of your next turn.
 * As an action, you can spend 1 ki point to invoke the effects of the "Alter self" spell for ten minutes. You do not have to concentrate on this feature, but may end its effects as a free action.

Shifting Phase
At level 6, you are able to force your body to exhibit rapid changes in size using your ki. As a bonus action, you may spend ki points to modify your body’s proportions, growing or shrinking your body.

When you do so, you may spend ki points to grow or shrink a size category per ki point spent, your size and weight doubling or halving per category. If there isn't enough room for you to double your size, you attain the maximum possible size in the space available. When you do so, your size category can range from small to large, granting you benefits while your size has changed. Your size remains changed for a minute or until you decide to revert to your normal size. When your size changes, you may choose to have your equipment and anything you are wearing change sizes with you. Any dropped equipment immediately returns to its normal size. When using this feature to become Tiny or Large sized, you gain the corresponding properties.
 * Shrink - Your speed is reduced by 5ft per size category shrunk, and have advantage on Dexterity rolls and Dexterity saving throws. When squeezing through a space, you do not spend additional movement.
 * Grow - Your speed is increased by 5ft per size category grown, and you have advantage on Strength rolls and Strength saving throws. Creatures occupying your space after growing are pushed to the nearest unoccupied space as you suddenly grow.

Enhanced Shifting Phase
At level 11, your ability to shrink and grow are further enhanced
 * Shrink - Spending a ki point, you may shrink as a reaction when you are attacked. When you do so, you may make a single attack targeting you miss.
 * Grow - When you grow, creatures within 5ft of you must succeed on a Strength saving throw equal to your Ki Save dc or be knocked prone.

Polyshape
At level 17, your body becomes flexible in its essence, conforming to your ki. You may invoke the effects of the "Polymorph" spell targeted on yourself using 5 ki points. When you do so, you retain your alignment, personality, your intelligence, wisdom, and charisma scores. While polymorphed, you may use any monk abilities your new form is physically capable of performing. You remain polymorphed for an hour, and you do not have to concentrate on this feature, but may end its effects as a free action.