As a giant creature with a monstrous body, you gain multiple benefits-- and downsides-- that make you both formidable and out of place in a world for people smaller than you.

Monstrous Body: Due to your physical form, you can't don most normal armors. Armors need to be specifically made for your form, and cost double to be made in this way. 

Heavy Hitter: With your hulking form, your attacks can have an extra bit of force behind them, if you so choose. When you hit a creature large or smaller with a melee weapon attack, you can force them to roll a strength save (DC 10+Prof) or be pushed back 10 feet and knocked prone. You can do this a number of times equal to your proficiency bonus, and all uses regenerate on a long rest. 

However changed you are, your roots still affect you. You gain a feature based on your original subrace. Choose one of these based on your character's origin.

Feng-Shi: Zheng Tu Daxue: Twice per short rest, you may add twice your proficiency bonus to a non-combat check of your choice, if you are proficient in the skill. If you are not proficient, you may instead add your proficiency bonus once.

Rajya: Giver of the Monsoon: Any direct healing effects from you heal for one extra dice. If they do not heal with dice, they heal for half their amount again. 

Oya-kin: Conquest-kin: Your critical strike range when dealing damage is increased by 1.

Impundulu: Wings over Water: When moving through water, your fly, swim, or base speed increases by 10 from clever navigation over water-born thermals and drafts.

Your body, through a great mutation, has become something far beyond natural form. With your new form, you gain new abilities. 

Mammalian: Your body is fused with that of a large mammal, like a lion or bear. Your speed increases by 5, and you gain claws as natural weapons, which deal 2d4 + your Strength Modifier Bludgeoning Damage.

Reptilian: Your body is fused with that of a great reptile, like a crocodile or gila monster. Due to this, your hide is covered in thick, heavy scales, giving you an unarmored AC of 13 + your Dexterity modifier, and you gain a tail as a natural weapon, which deals 1d8 + your Strength Modifier Bludgeoning Damage. 

Aquatic: Your body is fused with that of a giant fish or similarly aquatic creature, like a turtle or seal. You gain a swimming speed equal to your walking speed + 10ft, and you gain a bash as a natural weapon, which deals 1d8 + your Strength Modifier Bludgeoning Damage.

Insectoid: Your body is fused with that of an oversized insect, like a scorpion or spider. You gain a climbing speed equal to your walking speed +10ft, and you gain a bite as a natural weapon, which deals 1 + your Strength Modifier piercing damage + 1d8 poison damage. 

Avian: Your body is fused with that of a great bird, like an eagle or crane. You gain a flying speed equal to your walking speed +10ft, and you gain talons as natural weapons, which deal 2d4 + your Strength modifier slashing damage.

All natural weapons gifted by this feature can be affected by spells such as Booming Blade and True Strike that affect weapons (Not Shillelagh), due to your body's natural affinity to magic as a Fey Creature. 

You can see in dim light within 60 feet of you as if it were bright light and in darkness as if it were dim light. You discern colors in that darkness only as shades of gray.

Though your connection to the storms is weak, you still gain some benefits from this ancient connection. When you deal damage with a melee or ranged attack, you can choose to imbue that attack with the force of a thunderstorm. You turn all damage within that attack into either Thunder or Lightning damage, and deal an extra amount of damage equal to your proficiency modifier in the damage type of choice. You can do this a number of times equal to your proficiency modifier, and you regain all uses after a long rest.