A stat of your choice increases by 2, and another by 1

It is unknown just how long Bloodtied Dragons truly live for, with no known examples living to die of old age. However, it is rumored that they can outlast dwarves in lifespan, with a maximum potential of over 350 years

In their true form, a Bloodtied Dragon stands at around 7-8 feet in height, with a length of up to 25 feet and a wingspan 1.5-2 times this length. In their origin form, they vary depending upon their origin form, though the most common of these to become a Bloodtied is a human, with rare exceptions. Your size in your true form is Large, and your Origin form is Medium.

Carrying Capacity:

As noted in the PHB p. 176, Large creatures have double the carrying capacity.

Consumables:

Based on the food and water needs (DMG p. 111), Large creatures require four times as much food and water per day. Due to your magical nature, even goodberries only satisfy your hunger if you consume four of them.

Cover:

It should be harder for a Large creature to find cover (PHB p. 196). The DM will adjudicate this, but roughly speaking where a Medium creature would find total cover, a Large creature might only receive three-quarters cover; where a Medium creature finds three-quarters cover, a Large creature might only receive half cover; and where a Medium creature finds half cover, a Large creature might find none.

Your base walking speed is 25 feet in your true form. 

Your base walking speed is 30 feet in your origin form

Your keen Draconic eyes can see in the dark, you gain 60' of darkvision. You can not discern color in this range.

Your new form grants you wings upon your back to fly with. You gain a flying speed of 40 feet

Must keep moving
You lack the ability to hover in flight, while flying, if you do not move at least half your speed during your turn, you fall to the ground.

Alteration cost
You may not fly in normal backpacks or armor. The cost to alter your gear to be suitable for flight is equal to half the cost of the gear

Wingspan
You must be in a space wide enough to accommodate your wingspan to fly. Your wingspan is equal to 1.5 times your Height plus Length

Armor restrictions
You can not wear heavy armor and use this race feature

Your true form is quadrupedal in nature, though your forelimbs have grasping digits upon them by which you may influence the world. This presents a difficulty in handling manufactured weapons meant for two hands, as you require three to stand.

You can not utilize the two handed property in your true form.

Versatile weapons must be utilized in their one handed damage dice in your true form

You are treated as a medium creature for the purposes of wielding weapons.

As your form is far different from that of a humanoid, you require custom armor to suit your needs, requiring it to be altered at a cost determined by your DM

In your origin form; you have no changes to your weapon wielding capacity. Your armor does not change to fit your forms when you shift however.

You gain two natural weapon attacks. A bite attack, dealing 1d6+strength piercing damage on a hit, and a claw attack, which is a 1d6 slashing damage finesse weapon attack.You have proficiency in these attacks.

Your creature type is both Dragon and Shapechanger, with all the weaknesses and limitations they come with (ex, moonbeam reverting you to your origin form).

Your true form is your Draconic form

Your origin form is your humanoid form

As an action, you may shapechange between these forms

The time you can spend in your origin form is equal to 4 + proficiency mod hours per long rest

Any equipment you are carrying when you change forms falls to the ground harmlessly around you, other than you can wear a set of mundane clothes when you change to and from your origin form unless it is specifically enchanted to not (DM dependent on if such an enchantment or modification would exist in the world the character inhabits). This shedding of armor includes magical armors, as they were designed to change to humanoid shapes, unless specifically enchanted to shift with you. Items like rings, necklaces, and other non body type depending items can remain however.

Due to your original nature still being present in your new form, spells and abilities which affect humanoids still affect you

You speak read, and write Common and Draconic

You can use your action to make a magically charged roar. When you use this attack , each creature in a 15ft cone must make a Con saving throw, equal to 8 + your Constitution modifier + your proficiency bonus. A creature takes 2d6 thunder damage on a failed save, and half as much damage on a successful one. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 at 16th level. After you use your breath weapon, you can't use it again until you complete a short or long rest.