The Swarm

Vile hordes of rot grubs, devastating swarms of locusts, mosquitos, or flesh eating beetles.  Your patron is deeply connected to such things, and the natural forces that they represent.  They may be the powerful matriarch of such a swarm, the collective hive mind of a magical colony, or a dedicated spirit of nature.  They may play an important role in the local ecosystem, a vital force of decay and decomposition.  However, they could just as easily be a malevolent force of destruction and death, twisting the magic of nature to fit their own needs.  Whatever the case, the pact that you have made with this entity has granted you dark and unusual abilities, changing you into a soldier for the hive and a powerful host vessel for the forces under your command.  In return, they may demand that you constantly hoard a supply of valuable resources to send to the hive, or that you seed new colonies wherever you go.  Whatever it is that they ask, your duty as a servant will forever be the cost of your powers.

Expanded Spell List

The Swarm lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Swarm Expanded Spells

Spell Level	Spells
1st	feather fall, ray of sickness
2nd	animal messenger, blindness/deafness
3rd	conjure animals, stinking cloud
4th	confusion, giant insect
5th	cloudkill, insect plague

Heart of the Swarm

Your connection to the swarm of your patron has altered your body, and you have become both a soldier and a host for fellow members of your hive. Starting at first level, are resistant to poison damage, and have advantage on saving throws against being poisoned or diseased.

Starting at 1st level you can use your bonus action at the end of your turn to shift your form and become a part of the swarm.  This effect lasts until the beginning of your next turn.  The effect ends if you die, or are incapacitated.  Until this effect ends you gain the following benefits:

•You have resistance to bludgeoning, piercing, and slashing damage

•You ignore difficult terrain

•You are immune to being grappled, paralyzed, petrified, prone, restrained, or stunned

 You can't use this feature again until you finish a short or long rest

Putrid Infestation

Starting at 6th level you can draw upon the hoards within and attempt to infest a creature within range.  Using your action you can cause a swarm of large flesh eating beetles, maggots, or other insects to appear in the flesh of an enemy within 30 feet forcing them to make a Constitution Saving Throw against your spell save DC.  Constructs automatically succeed.  On a fail, the target takes 4d6 piercing damage, and is infested by 1d4 flesh eating insects.  The infestation lasts for 1 minute.  On a successful saving throw the creature takes half that damage and is not infested.  At the start of each of an infested creatures turns, it takes 1d6 piercing damage for each insect inhabiting it.  The target dies if it ends its turn with zero hit points as the insects consume it from the inside.  Any effect that cures disease kills all infesting insects.  The infestation ends early if the target dies, you die, or are incapacitated.  

Grotesque Incubation

Starting at 10th level, you have learned to use the nutritious flesh of the dead to fuel the growth of new forces.  When a creature affected by your Putrid Infestation dies, or when a creature dies within ten feet of you, you can use your reaction to fill their corpse with larvae to create swarms of insects, the statistics for which are in the Monster Manual.  This creature cannot be a construct or an elemental, and it must leave a consumable body behind.  When you use this feature on a dead creature, you use their body to produce a swarm of insects at the start of each of your turn for a number of rounds equal to your Charisma Modifier (Minimum of 1).

  The swarms follow your mental commands, roll initiative for the swarms as a group.  The swarms have temporary hit points equal to half your character level rounded down, and gain a special bonus to their attacks equal to your charisma modifier (Minimum of +0).  The corpse you infest has hit points equal to your character level.  It is immune to poison, psychic, and necrotic damage; has resistance to bludgeoning, piercing, and slashing damage; and vulnerability to fire damage.  If the corpse is destroyed it ceases to produce swarms of insects.

You can also attempt to use this feature on an undead creature instead of a corpse.  It must make a constitution saving throw against your spell save DC.  On a success it is unaffected and you waste the use of this feature.  On a failed save, the undead creature takes 4d6 piercing damage, and 1d6 piercing damage at the start of each of its turns.  It can repeat the saving throw at the end of each of turns, and on a successful save the infestation ends.  As normal, it produces an insect swarm at the start of each of its turns until it passes its saving throw, or the effect ends.  The swarms remain until the end of combat, or until they are all destroyed.

Once you use this feature you cannot use it again until you have taken a long rest.

Lord of the Hive

Starting at 14th level you have become physically altered at a basic level.  You are now immune to poison damage and the poisoned condition, as well as disease.  You can also cast swarm of insects once per day without expending a spell slot.