Crimson Demon

This subclass has all the same features as a regular sorcerer, except the twinned spell ability is slightly different. You can now use twinned spell on any spell, not just a single target spell. This allows you to double the effect of any spell, at the cost of 1 sorcery point per spell level. Crimson demons also lose the ability to turn sorcery points into spell slots, and also cannot use Careful, Distant, Extended, Heightened, Quickened, or Subtle spells. If you use the twinned spell ability, you take 1d8 of damage each time you use it. Twinned spell can be stacked on the same spell as many times as you want. If you die because of your own twinned spell, you instead remain stable at 0 hp. 

Elemental focus

When you choose this subclass at level 1, you must pick a damage type. You will have advantage on all spell casts with this damage type, and disadvantage when casting any other type of spell. 

Acid

Will grant advantage on all spells that deal acid damage, and disadvantage on all other spells. 

Cold

Will grant advantage on all spells that deal cold damage, and disadvantage on all other spells. 

Fire

Will grant advantage on all spells that deal fire damage, and disadvantage on all other spells. 

Lightning

Will grant advantage on all spells that deal lightning damage, and disadvantage on all other spells. 

Necrotic

Will grant advantage on all spells that deal necrotic damage, and disadvantage on all other spells. 

Poison

Will grant advantage on all spells that deal poison damage, and disadvantage on all other spells. 

Thunder

Will grant advantage on all spells that deal thunder damage, and disadvantage on all other spells. 

Strengthened empowerment

When using the Empowered Spell meta magic on a spell that matches your elemental focus, you deal critical damage automatically. This does not apply to any additional spells cast using twinned spell. 

Resilience

You gain full immunity to the damage type of your elemental focus. 

Twinned Spell

This ability replaces the twinned spell meta magic. Whenever you cast a spell with the same damage type as your elemental focus, you may use Twinned Spell to instead cast it twice, doubling the damage and all effects. Using this ability costs one sorcery point per spell level as well as 1d6+4 damage. You can stack this ability as many times as you want when you use it, but can only use it on one spell per long rest. Before you use this ability, you must have full concentration for a number of turns equal to the number of times you are going to use it on your spell.