These Sorcerers were Wizards in another life or they are Wizards that have memorized their spells to the point that no longer need a Spellbook. They. Have. Done. It. And now, the sky's the limit!

Spell Prep

At the 1st Level, on top of the Spells you get as a Sorcerer, you also have memorized up to 6 1st Level Spells that Wizards can use but Sorcerers can't. You can also learn more spells by reading books and preparing them like a Wizard. HOWEVER, you can only use these Prepared Spells by expending a Sorcery Point based on the Spell Level. For example: a 1st Level Wizard Spell costs 1 Sorcerery Point. A Level 2 Wizard Spell costs 2 Sorcerery Points. Because of this you cannot learn 9th Level Wizard Spells.

I Am My Own Warlock Patron

At the 6th Level, you gain the powers of a Warlock's Eldritch Evocations. You may choose 3 Eldritch Evocations from the Warlock table. You will gain one additional Evocation at the 7th, 9th, 12th, 15th, and 18th Levels.

Magic Aura Beam

At the 14th Level you have so much Magic flowing through you that you can channel it into an attack. As a Bonus Action you can sacrifice half your Sorcery Points and your Spell Slots to fire a beam of pure magic. The main target and anything up to 15 ft next to it must make a Dex Save of 10+your Charisma Modifier to only take 5d4 Force Damage or take 5d8 Force Damage.

Last Breath Aura Bomb

At the 18th Level upon failing 3 Death Saving Throws you may choose to make one last ditch move to take down the ones who struck you down. You explode in a bomb of pure magic energy and everything in a 90ft. radius must make a Constitution Saving Throw of 10+your Charisma Modifier or suffer 10d4 Force Damage. On a success the damage is reduced to 3d8 Force Damage.