School of Impatience

The pompous and scholarly ways of most wizards can often be tedious, and becoming a great mage simply takes too long. As a thaumaturge, you find ways to cheat your way through life by employing the help of fiends from the Lower Planes. Capable of ultimate evil and bearers of vast knowledge, these fiends will serve you as your somewhat-loyal minions by fighting on your behalf and dealing with your dirty work. As your mastery grows, they will develop an increasingly insatiable drive for mischief, and will expect their master to step up to their standards... or else. 

Thaumaturgy Novice

Beginning when you select this school at 2nd level, you develop an ease for lying, cheating and bullying your way through wizardry. You learn the Thaumaturgy cantrip and gain proficiency in either Deception or Persuasion. 

Minor Impfestation

Beginning at 2nd level, you find other uses for your Arcane talents and are able to summon imps from the Lower Planes to serve you. As an action, expending a spell slot of 1st level or higher, you can conjure up a number of imps equal to the spell slot's level, which appear in an unoccupied space you can see within 60ft of you. They share your initiative and are friendly to you but not your companions. They may take any action specified in their stat block before disappearing at the end of your turn. If attacking, they must target the creature closest to them immediately after being summoned. If the imps are in dim light or darkness, they make their attacks with advantage. If any of the imps' attacks reduce a creature to 0 hit points, that particular imp remains until it fails to reduce a creature to 0 hit points during its turn. 

Impulsive Companion

Starting at 6th level, you gain the almost unwavering allegiance of an imp lackey, which can be summoned as a 30 minute ritual. Appearing in an unoccupied space within range, the lackey uses the stat block of an imp. Your lackey acts independently of you, but it always obeys your commands. In combat, it shares your own initiative and can take any action specified in its stat block. The lackey is friendly to you and all your summoned devils, but hostile to all other creatures, and when instructed to attack it will always target the creature closest to it, disregarding any specification issued by you. If the lackey attacks in dim light or darkness, or within 10 feet of another imp, it does so with advantage. 
When the lackey drops to 0 hit points, it disappears, leaving behind no physical form. It reappears after it is resummoned.
As a bonus action, you can temporarily dismiss your lackey. It disappears into a pocket dimension where it awaits your summons. Alternatively, you can dismiss it forever. As a bonus action while it is temporarily dismissed, you can cause it to reappear in any unoccupied space within 60 feet of you. You can’t have more than one lackey at a time. 

Devoted Devils

By the time you reach 10th level, your influence amongst your evil servants has grown to such an extent that more powerful devils also wish to serve you. Controlling such devils requires more powerful magic on your behalf, which comes at great expense. You learn the Infernal Calling spell and add it to your spellbook if it is not there already. You are able to cast it once per long rest without expending a spell slot, but in doing so your maximum hit points are reduced by 1/3 until you finish a long rest. You instantly learn the devil's true name upon summoning, and it is friendly to you and all your summoned devils but hostile to all other creatures. You may also cast this spell normally using spell slots of 5th level or higher. 

Greater Impfluence

By the time you reach 14th level, your influence over your servants is immense. Your imp summons, including your lackey, double their hit points and gain a bonus to AC, attack rolls, and damage rolls equal to your INT modifier. Additionally, you can focus your influence on your lackey to imbue it with greater power. By inflicting any number of levels of exhaustion on yourself, you can cause your lackey to transform into a barbed devil for a number of turns equal to the number of exhaustion levels gained.