Pact of the Shadowcaller

A warlock class that focuses on summoning and conjuring dark entities given to him by his Patron. 

Voice of the Shadowcaller

At 1st level, you gain the ability to mentally communicate with any of your summoned creatures, despite not sharing a language. You also gain a permanent +5 CHA bonus to bending fiends and demons to your will, or maintaining control over them. In addition, you can double your proficiency in persuasion and deception when dealing with demons.

Abyssal Henchmen

You have the ability to quickly call for help from your Patron. At 6th level you can quickly summon a fiend to help in a situation. As an action you can cast Conjure Greater Demon once per long rest without using a spell slot. You can use the spell to summon any type of devil, demon, fiend, monstrosity or undead. Additionally, your Find Familiar spell now finds two familiars, they do not have to be of the same type.

Infernal Arcana

Beginning at 10th level, you can use your action to cast a spell through your summoned fiend, using your fiend as a spellcasting focus. Additionally, your Patron has twisted your magic to aid him in his army. You gain 2 fiendish spell slots. Fiendish spell slots are the same level as your Warlock spell slots but can only be used to cast spells from your expanded spell list or to use special abilities that come with your summoned fiend. You gain an additional spell slot at 15th and 18th level.

Dark Summoner

At 14th level, your time spent studying and being around demons and fiends has allowed you to summon double the number of creatures when using your summoning or conjuring spells. You no longer have to make any checks to maintain control over your summons, and your summons obey your commands without question.