Auroraborn's low density allows them to float as they desire, making them immune to non-magical difficult terrain. Magical difficult terrain, or difficult terrain caused by spells, continues to act as difficult terrain for you.

Your crystal core makes up all that you are, so all attacks on it you feel tenfold. However, your instinct to protect yourself makes actually hitting it a difficult task for enemies. Any attacks made directly to your core do x1.5 damage, but you can add a +4 Modifier and make a Dexterity check on any attack specifically aimed for your core to move it around your body and take normal damage instead. This applies even to auto-hit attacks or spells.

Starting at 1st level, your connection with the Weave guards your destiny. If you fail a saving throw or miss with an attack roll, you can roll 2d4 and add it to the total, possibly changing the outcome. Once you use this feature, you can’t use it again until you finish a short or long rest/Trance.

You have inexplicable luck that seems to kick in at just the right moment.

You have 3 luck points. Whenever you make an attack roll, an ability check, or a saving throw, you can spend one luck point to roll an additional d20. You can choose to spend one of your luck points after you roll the die, but before the outcome is determined. You choose which of the d20s is used for the attack roll, ability check, or saving throw.

You can also spend one luck point when an attack roll is made against you. Roll a d20, and then choose whether the attack uses the attacker's roll or yours.

If more than one creature spends a luck point to influence the outcome of a roll, the points cancel each other out; no additional dice are rolled.

You regain your expended luck points when you finish a long rest.

As a construct, you do not need to eat, drink, breathe, or sleep. However, the nature of your body type means you cannot maintain your gaseous form in vacuums, underwater, or windy weather.

Your Constitution raises by 2.

As a construct, you are technically ageless, formed fully 'grown'. Your mental and social maturity varies depending on surroundings and those you interact with, but Auroraborn are artificially immortal and can last forever so long as their cores remain intact.

Auroraborn want to find the joy and thrill in life, which makes them lean towards Chaotic alignments. They also usually mean little harm to mortals and rarely ever align outside of Good or Neutral.

Auroraborn can choose their own size, but the larger the crystal core, the larger they tend to be. Your size can range from 3 ft. to 10 ft.; Small to Large.

Auroraborn float most of the time, but their low density makes it difficult for them to move through the air quickly. Your base walking speed is 20 ft., and your base flying speed is 15 ft.

You see in enhanced colors unseen by other creatures eyes, giving you proficiency in visual Perception checks. You can also see in darkness up to 30 ft. in full color, and can see in magical darkness up to 10 ft. in grey hues.

By focused on the magical makeup of your body, you can become temporarily resistant to particular kinds of attacks. This ability lasts for 1 minute once per day or after a successful Trance/Long Rest and grants you resistance to bludgeoning, slashing, and piercing damage. 
Starting at level 4 you can use this ability twice a day; at level 8 you can use this ability three times a day; at level 12 you can use this ability four times a day; at level 16 you can use this ability five times a day.

You have advantage on saving throws against being charmed, and magic can’t put you to sleep.

You don’t need to sleep. Instead, you meditate deeply, remaining semiconscious, for 4 hours a day. (The Common word for such meditation is “trance.”) While meditating, you can dream after a fashion; such dreams are actually mental exercises that have become reflexive through years of practice. After resting in this way, you gain the same benefit that a human does from 8 hours of sleep.

You can speak, read, and write in Common, Sylvan, and Celestial.