Dark Spawn

You conjure energies from the Shadowfell and infuse it into your own shadow, forming it into a Dark Spawn that is under your control. This creature spawns in an unoccupied space of your choosing within 60 ft. of you. It can take whatever form you choose. If no form is chosen, it defaults its shape to be a mirrored image of you. While this Dark Spawn exists, you cast no shadow.

The Dark Spawn has an AC of 10. The amount of Hit Points it has is determined by rolling an amount of d8 dice equal to the level of the spell slot expended when casting this spell. On your turn, a Bonus Action can be used to teleport the Dark Spawn into an unoccupied space up to 30 ft. away from its current position. It will fade prematurely if its Hit Points are reduced to 0, if you are made unconscious, if you die, or if you lose concentration. Your Dark Spawn has one or more of the following abilities depending on the level of the spell slot expended when casting this spell:

Shadow Strike. When cast at 1st Level or higher, your Dark Spawn has this ability. As either a Bonus Action or as part of its teleporting movement, your Dark Spawn can make a melee attack against a creature within 5 ft. of it. When made as part of a teleport movement, this attack can take place either before or after it teleport. This attack deals an amount of Necrotic damage on a hit equal to 1d10 + your Spellcasting Ability Modifier. 

Shadow Veil. When cast at 2nd Level or higher, your Dark Spawn has this ability. A 20 ft. spherical aura is centered around the Dark Spawn. This aura is treated as heavily obscured and/or difficult terrain to any creature of your choosing that enter it. Whenever your Dark Spawn teleports, it can take any creature within its aura along with it, placing the taken creature in an unoccupied space of your choosing within 20 ft. of your Dark Spawn's new position. An unwilling creature must make a Charisma saving throw to resist being teleported (DC = 8 + your Proficiency Bonus + your Spellcasting Ability Modifier).

Shadow Trick. When cast at 3rd Level or higher, your Dark Spawn has this ability. If you are targeted by an attack or harmful effect, you can use a Reaction to switch places with any creature within your Dark Spawn's Shadow Veil ability to avoid harm, including the Dark Spawn itself. The creature you switch with then becomes the target of the oncoming attack or effect, instead of you. An unwilling creature must make a Charisma saving throw to resist being switched. A creature hit by your Dark Spawn's Shadow Strike ability since the start of your previous turn makes this saving throw with disadvantage.

Shadow Flay. When cast at 4th Level or higher, your Dark Spawn has this ability. Any creature of your choosing that moves into or starts its turn within the Dark Spawn's Shadow Veil aura must make a Constitution saving throw. Upon a failed save, a creature is dealt 4d10 of Necrotic Damage. Upon a successful save, a creature is dealt half as much damage. A creature hit by your Dark Spawn's Shadow Strike ability since the start of your previous turn makes this saving throw with disadvantage.

Shadow Cloak. When cast at 5th Level or higher, your Dark Spawn has this ability. You can use a Bonus Action on your turn to have the Dark Spawn touch and envelop one creature within 30 ft. of it (yourself included). On your turn, a Bonus Action can be used to separate the Dark Spawn from a creature it is enveloping in this way, teleporting the shadow into an unoccupied space up to 30 ft. away from that creature's current position. The Dark Spawn cannot be harmed when enveloping a creature.

When enveloping a creature, your Dark Spawn cannot use its Shadow Strike ability, and the distance and damage of its Shadow Veil and Shadow Flay abilities are reduced to 10 ft. and 2d10, respectively. However, the creature it envelopes gains the following benefits:

• The creature receives a +1 bonus to its AC and its saving throws.
• The creature can see as far as 30 ft. in both magical and non-magical darkness. If it already has darkvision, the first 30 ft. of its vision can now see in magical darkness. 
• The creature's non-magical weapon attacks become magical for the purpose of overcoming resistance and immunity to non-magical attacks and damage.
• The creature can add a 1d10 of Necrotic damage to the damage roll of its weapon attacks made in bright light. Attacks affected in this way count as a Shadow Strike.
• The creature can add a 1d10 to the attack roll of its weapon attacks made in dim light or darkness. Attacks affected in this way count as a Shadow Strike.
• The creature can add a 1d10 to any concentration checks it makes.