To Sacrifice others for power or to Save others at the cost your life for them. The power to do both lie within your dominant arm and is up to you to shape. Beware the consequences however as this power will reflect the core of your being. This power manifests in three ways:

1. From Birth: This power is passed onto to you from your family's bloodline.

2. Infection: This power manifests from when you faced a wielder of this power and prior to their death they attempted to use their power to take your body and failed, resulting in their death and your gain of their power.

3. Transplant: After suffering injury and loss of limb, an Arm of Sacrifice is transplanted onto your body.

Sorcerer's with this ancient and hated power use it to their own benefit or perhaps the benefit of others depending on their decisions. With how versatile this power is, those who do not mind the disfigurement covet this power greatly and some more insane magic researchers hunt wielders of this arm and cut them off to research them.

Manifestation

At 1st level your dominant arm has already began to show signs of manifesting your core as well as mysterious runes in a lost language glowing on it as you cast spells granted to you by the Manifestation. Your arm takes traits based on your alignment and grants a boon based on said traits.

Primary Alignment:

Lawful: Your arm has a silver aura about it. Your boon is +1 Spell Save DC

Neutral: Your arm shows no signs of change other than the runes. Your boon is +1 Concentration Checks

Chaotic: Your arm has gained a red hue and twisted appearance. Your boon is +1 on attack and damage rolls

Secondary Alignment:

Good: White feathers flourish whenever you cast spells and your runes are blue. Your boon is you may add 1d6 Radiant damage to one spell per short rest

Neutral: Your arm shimmers like a mirage when you cast spells and your runes are green. Your boon is you may add 1d6 Psychic damage to one spell per short rest

Evil: Black smoke is emitted from your arm when you cast spells. Your Boon is you may add 1d6 Necrotic damage to one spell per short rest

All damage die boons is increased by one every third level. (4th, 7th, 10th, 13th, 16th, and 19th)

Sacrifice

Starting at 2nd level, should you slay an enemy with a melee attack or with a spell and they are within five feet of you, you may use your reaction to Sacrifice them before they fully die. This takes one full round and while doing this, attacks made against you have advantage and a concentration check is required to continue to do so. Success will cause the body to explode before being absorbed into your arm, granting you Sorcery Points equal to half of the target's CR, minimum of one. This ability can only be used once every ten rounds and cannot be used one creatures that are above Large in combat. All Sorcery Points gained by this ability disappear upon resting.

DM Note: You may change the alignment of a character towards Evil if they abuse this power

Save

Starting at 2nd level, should you slay an enemy with a melee or spell and they are within five feet of you, you may use your reaction to Save them at the cost of their CR times your Sorcerer Level hit points to stabilize them. This takes one round and all attacks made against you have advantage but does not require a concentration check. This can also be used to stabilize allies. At an additional cost you may sacrifice extra hit points to give to the target. Upon success you gain Sorcery Points equal to the target's (Level if the target is a player), minimum of one. This ability may be used once every five rounds and cannot be used on creatures above Large in combat. Sorcery Points gained by this ability disappear upon resting.

DM Note: You may change the alignment of a character towards Good if they abuse this power

Increased Manifestation

At 6th level damage die from Manifestation become d8 and the changes from become more intense and grant an additional boon but also come with a detriment.

Lawful: Your arm now shines with a moon like glow. You can use Save every three rounds but you have disadvantage on Stealth checks

Neutral: Your now draws in all the bad luck from your surroundings. You gain the Lucky feat but using it gives you disadvantage on your next turn.

Chaotic: Your hand becomes a claw and horn like protrusions grow from out of your skin. You can use Sacrifice once every five rounds but have disadvantage on Persuasion checks

Lacrima

At 14th Level, you can crystalize half of the Sorcery Points you have gained from Sacrifice and Save and store them away for later. Lacrima can be used to gain Sorcery Points or heal wounds but require concentration and one round if used in battle. Sorcery Points gained by Lacrima only last an hour. Also Sorcery Points gained by Sacrifice and Save can be used to heal yourself

Forbidden Arcanum Manifestation

At 18th Level all damage die from Manifestation become d10 and you gain the power to fully Manifest your power by sacrificing half your max hit points and disfiguring yourself by sacrificing something. The Manifestation is dependent on your alignment.

Lawful: Sacrifice your eye or skin off your legs to gain wings of light that do 2d6 radiant damage to all creatures within ten feet if they start in the radius or enter it. Your flight speed is 40 ft.

Neutral: Sacrifice skin off both your arms to grow sacrifice four bladed appendages that grow out of your back. You gain an attack for each appendage at the cost of your regular action giving you four attacks and each blade 1d8 Slashing and 1d4 Psychic. They can't be used for Attacks of Opportunity

Evil: Sacrifice your skin from your chest and back to manifest your shadow as a doppelganger with all of your stats, spells, and spell slots that moves right after you.

All Forbidden Arcanum last ten minutes and hit points that are paid to create them can only be recovered via Sorcery Points gained by Sacrifice or Save or by using Lacrima. Multiple uses of Greater Restoration can close the wounds allowing the hit points to be recovered naturally (One cast per 20 hit points lost). Until the damage is fully healed, you cannot use Forbidden Arcanum.