Optimized Shadow Sorcerer (5e Optimized Character Build)
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For this build, we are going to need an elven ancestor, so pick Half-Elf or Elf. I would prefer Half-Elf, since +2 Charisma is better for a sorcerer.
Str: not mandatory, wouldn't recommend putting it high
Dex: Quite useful if it is high, especiall to counter playing without armor.
Con: Good since you only gain d6 Hit Dice as a sorcerer
Int: not mandatory
Wis: not mandatory
Cha: As high as possible
We will be Monoclassing in Sorcerer, because we don't really gain anything extremely useful from multiclassing, and are taking the Shadow Sorcerer subclass.
I would recommend you to take Quickened Spell and Twinned Spell, but this is not necessary so choose whatever you prefer.
You don't need to take Darkness, since you'll learn it at Level 3 automatically. I would recommend the normal spells like Shield and Fireball, and try to mostly take damaging spells that have an Attack Roll, since this is what will make you truly overpowered. For example, Chaos Bolt and Firebolt are really strong.
Ability Score Improvements
Since we don't really need higher abilites that much, we'll be going to the feat-territory.
Level 4: Elven Accuracy: This will allow use to basically roll 3d20 for Attack Rolls instead of 2d20 if we have advantage.
Level 8: Magic Initiate: If you want better spells, take some Warlock Spells with this, so it still casts with Charisma. My favorite: Toll The Dead, Eldritch Blast, and as the Spell Hex or Guiding Bolt.
Level 12, 16, 19: We won't be needing anything else, you can again take Magic Initiate if you want even more spells, Spellsniper if you want to attack from further away, or just improve Charisma or other stats if they aren't as high as you would want.
A nice trick, Darkness is a 2nd level spell. As a sorcerer, you can turn those into 3 sorcery points. Now, when you cast them as a Shadow Sorcerer with sorcery points, it only costs 2. Additionally, you can see trough the darkness which is the main reason this build even works. So, you not only cast the spell cheaper, it makes you extremely strong.
First, you cast Darkness with your 2 sorcery points. Normally, everyone has disadvantage attacking and advantage being attacked, so it cancels out. Since you aren't able to be seen, every creature inside and outside the darkness can't see you (->Disadvantage Attacking you), but you can see them (->still advantage attacking them). Trough the Elven Accuracy Feat, you can now roll 3d20 on attack rolls while in your Darkness. Keep in mind that darkness is Concentration, but for Attack Spells, this is no problem.
So in conclusion, you have a 15% chance of critting, everyone has disadvantage attacking you and at level 14, you can basically be faster than most Monks trough the Shadow Step, since you can move 180 ft in a round (or 150 ft and you can still cast Spells).