Risen

Sprouting Risen

Starting at 3rd level, the growths within you have filled your body with unnatural vitality. You can use your Second Wind twice between rests. When you finish a short or long rest, you regain your expended uses.
Additionally, when you use your Second Wind feature to regain hit points, vegetal adaptations burst from under your skin. Until the start of your next turn, whenever you take damage equal to or less than the hit points you regained using your Second Wind feature, you can reduce that damage to 0.

Walking Copse

Also at 3rd level, the wood within has changed you. While in sunlight, you can sunbathe instead of sleeping, remaining semiconscious, for 4 hours. To gain the benefits of a long rest, you can spend all 4 hours doing light activity, such as relaxing or keeping watch. After resting in this way, you gain the same benefit that a human does from 8 hours of sleep, and are nourished enough to sustain yourself for another day.

Corpse Seed

At 7th level, you learn to spread the wood within you. As an action, you can touch the coprse of a Small or Medium beast or humanoid and plant a seed inside it. After 1 minute, the seed germinates, and the corpse stands as a husk. The husk has the same statistics as a zombie (MM 316), though it is a plant instead of an undead, and has vulnerability to fire damage.
Each husk is friendly to you and your companions, takes its turn on your initiative, and obeys your verbal commands. If you don't issue any commands to a husk, it pursues and attacks the nearest hostile creature to the best of its ability.
A husk sustains itself only on your power. You can't sustain more than three husks using this feature at a time. If you plant a seed inside a corpse while you already have three husks from this feature, one of the husks under your control withers and dies.

Burrowing Roots

Starting at 10th level, when you start your turn on solid ground, you can root yourself into the earth until you die or until you uproot yourself (no action required). While rooted, your speed is 0, you can't be moved, pushed, pulled, or knocked prone, and you have advantage on Dexterity (Stealth) checks you make to hide amongst plants.

Innervate

By 15th level, the wood within has twined around your heart, filling you with life. Whenever you regain hit points, treat any dice rolled to determine the hit points you regain as having rolled their maximum value for you.
Additionally, you suffer none of the frailty of old age, and if you die of old age, the growths within you tear your heart from your body and plant it as a seed deep within the earth, growing a great forest from the place your heart was buried.

Overflowing Life

Starting at 18th level, when you die, your corpse can animate, puppeteered by the growths inside you. Your corpse can't animate if you died of old age. Your corpse has your statistics, though it has hit points equal to half your hit point maximum, and is a plant. Its Intelligence and Charisma scores are 1, and it can't cast spells, activate magic items, understand language, or communicate in any intelligible way.
Your corpse takes its turn on your initiative, and you determine its actions and decisions. Your corpse can identify your companions as allies, follow them, and protect them.
If your corpse sunbathes for 4 hours using your Walking Copse feature, you are returned to life with 1 hit point. If your corpse is reduced to 0 hit points, the plants animating you wither, and it becomes an ordinary corpse.
Once your corpse animates, it can't animate again until you finish a long rest.