Archfey are known to take on other forms, for example Titania taking the form of a nymph, to have trysts with lesser beings.  Sometimes the offspring of these unions inherit a portion of their fey parent's power and their capricious/ whimsical personality.  Other times the offspring appears to be a typical member of a lesser fey or mundane race, but one or more of their descendants may manifest these fey traits.  Fey Soul sorcerers are often mistaken for bards or Divine Soul sorcerers with a creative streak.  The latter is understandable since the difference between an Archfey and a deity is in large part personality and acquaintances.

Fey Magic

Your fey ancestry allows you to learn spells normally associated with the bard class. When your Spellcasting feature lets you learn a sorcerer cantrip or a sorcerer spell of 1st level or higher, you can choose the new spell from the bard spell list or the sorcerer spell list. You must otherwise obey all the restrictions for selecting the spell, and it becomes a sorcerer spell for you.

In addition, you learn the Faerie Fire spell. It is a sorcerer spell for you, but it doesn't count against your number of sorcerer spells known. If you later replace this spell, you must replace it with a spell from the bard spell list.

Fey Guide

You learn the find familiar spell and can cast it as a ritual. The spell doesn’t count against your number of spells known.

When you cast the spell, you can choose one of the normal forms for your familiar or one of the following special forms: pseudodragon or sprite.

Additionally, when you take the Attack action, you can forgo one of your own attacks to allow your familiar to make one attack of its own with its reaction.

Misty Escape

Starting at 6th level, you can vanish in a puff of mist in response to harm. When you take damage, you can use your reaction to turn invisible and teleport up to 60 feet to an unoccupied space you can see. You remain invisible until the start of your next turn or until you attack or cast a spell.

 

Once you use this feature, you can’t use it again until you finish a short or long rest.

Otherworldly Wings

Starting at 14th level, you can use a bonus action to manifest a pair of spectral wings from your back. While the wings are present, you have a flying speed of 30 feet. The wings last until you’re incapacitated, you die, or you dismiss them as a bonus action.

The spectral wings appear to be dragonfly/fairy wings.

Archfey

Starting at 18th level, you have transitioned into a lesser Archfey. Your creature type becomes fey but you do not lose access to any of your feats that required your previous race.  However you no longer qualify for new feats that required your previous race.

Your overall appearance changes to resemble either an eladrin or fairy.  Your eyes glow with swirling iridescent colors.

You become youthful and slender.  Moreover you no longer age.  You become immune to magical aging and the charmed effect. 

You gain advantage on charisma saving throws. 

You manifest the ability to act as your own arcane focus. When casting spells, you can now ignore the material component that lack a cost and aren't consumed by a spell.

When in the feywild you gain advantage on all saving throws and can cast metamagic without expending sorcery points.

Fey Presence 

You manifest the ability to project the beguiling and fearsome presence of the fey. Once per round as an action, you can cause each creature in a 10-foot cube originating from you to make a Wisdom saving throw against your sorcerer spell save DC. The creatures that fail their saving throws are all charmed or frightened by you (your choice) until the end of your next turn.