While most demigods appear as normal humans - maybe taller or stronger than average, but still normal - they have the blood of gods. They are the product of a deity and a mortal lover, and thusly are imbued with abilities beyond what is considered natural. If an enemy of the pantheon or their holy parent's spouse were to find the mark of a divine on them, they're considered good as dead. 

More Than Human

What really makes a demigod is their combination of mortal and divine genes. Depending on their deific origins, a demigod could appear as a perfectly normal person, or a supernatural and almost monstrous being. Their godly parentage will manifest in various ways, depending on the parent's domain, so the child of a love god will look very different from that of a sky god. The most common outlets of this effect are eye color, hair color and shape, personality, and abilities, but sometimes it can affect things like anatomy and skin tone. 

Edge of Immortality

As a mix of an immortal and a mortal, demigods are similar to a pearl forming in an oyster because, within a mortal shell, potential godhood lies dormant. This is more obvious through demigods' blood being ichor instead, but as they become stronger and wiser, it will show through their aging process, their lifespan, and their aura. Legends tell of fully realized half-gods who killed their mortal half, attaining immortality and godhood, describing such legendary figures as Heracles, Hermes, and Dionysus. 

Guided Destiny

Very rarely do demigods live life unaware of their superior heritage, as the strings of fate and the eyes of other gods are bound to unearth their origins sooner or later. Perhaps their holy parent has an infuriated spouse, or a prophecy tells of a half-god hero just like them, or maybe they knew of their importance from the very beginning, but eventually, demigods find themselves on the path to destiny. Some strive to overcome their fatal flaw, while others wish to realize their godhood, while still others aim to put their unique abilities to good use, but mostly every demigod is drawn by wanderlust. 

Demigod Names

Demigods oftentimes take native names from their mortal parent's race, but in cases such as abandonment or renaming, they may take on divine names or adjectival nicknames. In the case of a divine name, the structure of the name will be derived from whatever language is native to the culture that worships the pantheon you hail from.

Demigod Traits

Languages

You can speak Common and Celestial, and at level 5, Primordial as well.

Ability Score Increase

Your Strength score increases by 2, and your Wisdom score increases by 1.

Age

Demigods age at the same rate as their mortal parent's race, but can stop their aging process or become immortal if they ascend.

Alignment

Demigods often lack any sense of neutrality, usually becoming extremely chaotic or strictly lawful, and either perfect paragons or despicable villains.

Size

While often medium, demigods' sizes can very depending on the nature of both parents.

Speed

Your base walking speed is 20 feet.

Godly Contacts

Once after a charging period of one long rest, you can contact your godly parent and request gifts, assistance, boons, blessings, or advice. This must be conducted using a conduit of some type that is related to the god's domain, like a seashell for a sea god, or a bloodied blade for a war god. The communication between them and you can only be heard in your own mind. When first granted, this ability can only allow you to ask simple yes or no questions or request small non-magical items, but with each level up, you become more in tune with the ability until you may be able to summon the god's spirit to fight with you.

Minor Blessing

Thanks to your divine heritage, you have inherited a minor yet superhuman ability, similar to Bellaraphon inheriting equine mastery from Poseidon, rather than mastery of the seas. As you level up, your blessing may increase in strength, or more features may awaken.

The Final Ascension

After rigorous training and a merciless journey, you have surpassed your mortal half. You have become fully immortal and have risen to minor godhood, gaining your own abilities and designations. As a minor god, you can still die, but only at the hands of Infernal weapons - or Celestial if the god you come from is Infernal instead. You no longer age and the bronze-colored ichor-blood you had before is now the vibrant gold ichor of a god. To attain ascension, you must throw away your humanity, embracing divinity, and thus no longer being able to directly participate in mortal affairs. You can assist from afar, sending messages and boons, but your physical presence in the mortal plane is heavily limited.