The exact bargains struck by a diabolist determines what it looks like when they use one of these features, but ultimately what that looks like is up to you. If you are a Voidfallen it might appear that flumphs are what Carry you about, or if you’re an Infernalist then imps do the job.
Conjuring and Thralls. You cannot have a thrall summoned and also cast a conjuration spell that summons a creature (this does not include faithful hound, find steed, or insect plague). When you do, the thrall disappears (or vice versa).
Winged creatures partially phase into reality to briefly pick you up and carry you aloft. You can use a bonus action and expend 1 diaboli point to gain a fly speed equal to your proficiency bonus × 10 feet. This fly speed lasts for a number of rounds equal to your proficiency bonus. If you do not end your turn on a solid surface at the end of the duration you fall as normal.
Prerequisite: 10th level
You can use an action and expend 5 diaboli points to beckon forth a hungry entity not of the Material Plane, allowing it an instant to reach its head into reality to eat the head of a foe presented to it. Make a ranged spell attack against a bloodied creature you can see within 120 feet. You have advantage on this attack. On a hit, the creature takes 10d12+8 magical piercing damage as a terrible monster bites down on it just before disappearing. If this reduces the creature to 0 hit points it is decapitated and its head ceases to exist.
Prerequisite: 7th level
You can cast banishment or hallow (evil options only) by expending 4 diaboli points.
Spectral arms rise up from below to grab onto a number of creatures you can see within 60 feet equal to the number of diaboli points you expend to use this Manifestation. You can use an action to make a Grapple basic maneuver against each creature, using your spell save DC instead of your maneuver DC and your spellcasting ability to calculate your basic maneuver damage. A grappled creature remains grappled for 1 minute or until it uses an action to succeed on a Strength or Dexterity saving throw against your spell save DC.
Prerequisite: 10th level
You can cast conjure elemental or insect plague by expending 5 diaboli points.
Prerequisite: 5th level
You can use an action and expend 3 diaboli points to rip open a portal from which an enormous clawed hand emerges. Choose an area of dirt up to 30-feet square, an area of stone up to 15-feet square, or a creature or object of Huge size or smaller that is within 50 feet. You move the target up to 50 feet away. If you move a creature with the hand, it can use its reaction to make a Strength saving throw to resist. On a success it takes force damage equal to your proficiency bonus × 1d12 but is not moved. After making its swipe the hand withdraws into the portal which snaps shut immediately after.
Phantom tails and tentacles phase into existence to whip out at the legs of a number of creatures you can see within 60 feet equal to the number of diaboli points you expend to use this Manifestation. You can use an action to make a Knockdown basic maneuver against each creature, using your spell save DC instead of your maneuver DC and your spellcasting ability to calculate your basic maneuver damage. On a failed save a creature is knocked prone and takes 1d8 force damage, or on a failure by 5 or takes double damage.
Prerequisite: 3rd level
You can use an action and expend 1 diaboli point to conjure forth a wave of unnatural arms that spread your Necrotic Touch outward in a 30-foot cone. Each creature in the area makes a Charisma saving throw, taking your Necrotic Touch damage on a failure. You may use your Diabolic Strike with Lash, but you must choose to do so for every creature.
Prerequisite: 5th level
You can cast conjure animals by expending 3 diaboli points.
You can use an action and expend 1 diaboli point to briefly summon the limb of a servant beyond the realms material to pluck an item from somewhere nearby then deliver it to you. Use your spellcasting ability to make a Sleight of Hand check against a creature you can see within 100 feet. Unless the creature is under the effects of detect magic or otherwise able to see magical auras, you gain an expertise die on this ability check. On a success the item disappears with the limb which instantly reappears nearby, stowing it on your person.
You may select this Manifestation a second time, increasing its range to any creature you can see.
Prerequisite: 12th level You can cast conjure fey or planar ally by expending 6 diaboli points.
Prerequisite: 7th level, Grapple
You can use an action and expend 3 diaboli points to summon up just enough of a horde to grasp onto a foe and pin it down. Make a Grapple basic maneuver against a creature of Huge size or smaller that you can see within 60 feet, using your spell save DC instead of your maneuver DC and your spellcasting ability to calculate your basic maneuver damage. The creature has disadvantage on its saving throw. On a failed save it is grappled, prone, and restrained (escape DC equal to your spell save DC) until the end of your next turn. At the start of your turn you can use a bonus action to expend 1 diaboli point, extending the duration by 1 round. The creature repeats the saving throw at the end of each of its turns, ending the Manifestation on a success.
Prerequisite: Grapple or Knockdown Manifestation
When using the Grapple or Knockdown Manifestation you can expend a number of additional diaboli points equal to the number of creatures targeted. For each diaboli point expended in this way, one creature targeted by the Manifestation makes a Charisma saving throw, taking your Necrotic Touch damage on a failure. You may use your Diabolic Strike with Spreading Touch, but you must choose to do so for every creature targeted by it.
Prerequisite: 7th level
You can cast conjure minor elementals, conjure woodland beings, or faithful hound by expending 4 diaboli points.
Prerequisite: 7th level
You can cast black tentacles by expending 4 diaboli points.
Prerequisite: 14th level
You can cast plane shift or teleport by expending 7 diaboli points.