As two actions, you utter foul words and consume a vial of blood from a celestial or humanoid killed within the past 24 hours to summon a fiend in an unoccupied space that you can see within 10 meters. The fiend is neutral to you and your companions, and it disappears when it drops to 0 health or when the spell ends. The fiend can’t use any legendary actions or lair actions. Any spell cast by the fiend reduces your mana by the amount the fiend expends.
You can call two Abyssal Wretchs, Dretch, Imp, Maw Demon, Nupperibo, or Quasit
Any creature you animated with this spell acts after your turn. You can mentally command the creature if it is within 20 meters of you (if you control multiple creatures, you can command any or all of them at the same time, issuing the same command to each one). The creature(s) will generally follow any specific verbal commands that you issue to them if the likely outcome is in accordance with its desires (no action required by you). For example you may command it to guard a particular chamber or corridor, explore the room ahead, or to attack a specific creature. If you don't issue any commands, they defend themselves from hostile creatures, but otherwise take no actions.
Fiends prefer commands that would draw you toward evil. Otherwise, you must make a Deception, Intimidation, or Persuasion check contested by its Insight check. You make the check with advantage if you say the fiend’s true name. If your check fails, the fiend is immune to your verbal commands for the duration of the spell and may become hostile, though it can still carry out your commands if it chooses. If your check succeeds, the fiend carries out your command.
If your concentration ends before the spell reaches its full duration, the fiend doesn’t disappear if it has become immune to your verbal commands. Instead, it acts in whatever manner it chooses for 3d6 minutes, and then it disappears.
If you possess an individual fiend’s talisman, you can summon that fiend, and it obeys all your commands, with no Charisma checks required.
As part of casting the spell, you can form a circle on the ground with the blood used as a material component. The circle is large enough to encompass your space. While the spell lasts, the summoned fiend can’t cross the circle or harm it, and it can’t target anyone within it. Using the material component in this manner consumes it when the spell ends.
You can call two additional Abyssal Wretchs or one additional creature for each additional mana expended.
You can expend 1 additional mana to call a Barghest, Hell Hound, Incubus, Merrenoloth, Rutterkin, Succubus, Spinagon, or Vargouille. You can call one additional creature for each additional mana expended.
You can expend 1 additional mana to call a Babau, Hamatula, Barbazu, Bulezau, Cambion, Dybbuk, Gnoll Fang of Yeenoghu, Nightmare, Merregon, Mezzoloth, Night Hag, Shadow Demon, or Tanarukk. You can call one additional creature for every two additional mana expended.
You can expend 2 additional mana to call a Barlgura, Chasme, Vrock, or White Abishai. You can call one additional creature for every two additional mana expended.
You can expend 3 additional mana to call a Armanite, Black Abishai, Dhergoloth, Draegloth, or a Maurezhi.