The Sorcerer

Golden eyes flashing, a human stretches out her hand and unleashes the dragonfire that burns in her veins. As an inferno rages around her foes, leathery wings spread from her back and she takes to the air.
Long hair whipped by a conjured wind, a half-elf spreads his arms wide and throws his head back. Lifting him momentarily off the ground, a wave of magic surges up in him, through him, and out from him in a mighty blast of lightning.
Crouching behind a stalagmite, a halfling points a finger at a charging troglodyte. A blast of fire springs from her finger to strike the creature. She ducks back behind the rock formation with a grin, unaware that her wild magic has turned her skin bright blue.
Sorcerers carry a magical birthright conferred upon them by an exotic bloodline, some otherworldly influence, or exposure to unknown cosmic forces. One can’t study sorcery as one learns a language, any more than one can learn to live a legendary life. No one chooses sorcery; the power chooses the sorcerer.

In The Nameless Trilogy World

Magic fills the world, and can be accessed through a variety of ways. While some choose to study it, either academically or by their lifestyle, and others access it through divine means, the sorcerer stands out as a caster with a particular bloodline that is attuned to the ways of magic. The sorcerer presents a unique case in modern society. Their magic is neither meritorious nor academic. It is a flash of lightning in the middle of the night, at once illuminating and blinding. Where does it come from, no one really understands. 
How does the sorcerer fit into the world where science and technology have advanced to such degrees. Where ships and trains are powered by coal, rudimentary electricity lights the streets, and magical trinkets produced by artificers and wizards are used in everyday life, the sorcerer is seen as wild as the magic that they summon. Sometimes they are rejected by society, sometimes they are treated with extreme caution. People don't like things they don't understand, nor do they like things they can't control. The sorcerer represents both of these aspects, with magical powers that weren't earned through regular study, and wild surges of energy which even they struggle to contain. 
Consider these if you are thinking about a sorcerer. How did they acquire their magic, and how do they use it? Are they in full control of their magic, or are they sometimes caught by surprise? Your character will be going on a long journey with others. How will they serve the party with their magic? If things go wrong, how will they make it right?

Resources:

• Player's Handbook
• Xanathar's Guide to Everything
• Xanathar's Lost Notes to Everything Else

Subclasses:

• Draconic Bloodline (PHB)
• Wild Magic (PHB)
• Divine Soul (XGtE)
• Shadow Magic (XGtE)
• Storm Sorcery (XGtE)
• Fey Magic (XGtE)