School of Demonology

masters of demonic summoning, the school of demonology focus on making demon summoning effective and (slightly) less dangerous. compared to other minions like those of the school of necromancy, demons offer unique and powerful abilities to those willing to risk it. 

Dark ritual

At 2nd level, your knowledge of demons allow you to summon them to this realm. This works like casting a ritual, and takes you 10 minutes to complete. Using your spell casting focus, the ritual summons a demon of your choosing, with a CR equal or lower to half your level rounded down. When summoned, the demon makes a charisma saving throw against your spell DC. If failed you may give it a command (no action required on your part)that it will complete to the best of its ability. Once a task is finished or an hour has passed, the creature can attempt the saving throw again. if the saving throw is successful, then the demon is immediately hostile towards all nearby creatures and will no longer obey any commands, as well as abandoning any tasks it is currently completing. it will move to attack the nearest none demon to the best of its abilities. You may banish the demon by repeating the ritual, or killing the demon. A banished demon disappears, and any objects or equipment it has that it didn't have when summoned falls to the ground. When the demon is summoned you may make an intelligence (arcana) check with a DC of 10+(summoned demon's CR.) if passed then you learn the demons true name or in the case of lesser demons, successfully strengthened the binding on the demon, the demon will make any saving throws to control it at disadvantage. you may use this feature a number of times equal to your intelligence modifier (minimum of once). you regain all uses after a long rest. you may have no more then 1 demon summoned at once with this feature.

Demonology Savant

Beginning when you select this school at 2nd level, you learn methods to protect yourself while working with demons. You can cast magic circle as an action, however you may only choose fiends as per the spells description. after using this feature, you may use it again after completing a short or long rest. if you ever learn this spell, you may cast it with the same restrictions and benefits listed here. this does not use up a use of the class feature. In addition you can speak Abyssal

Powerful Binding

at 6th level, you add the "summon lesser demons" to your spell book if it is not there already. when you cast summon lesser demons, you may choose the d6 result on the demons summoned table. in addition, you can choose the type of demons summoned. demons of CR 1 or less are friendly to you, and will obey your commands without question. 

whenever you summon demons the following applies: 

-they add your proficiency bonus to their attack rolls

-demons summoned by spells stay for an amount of additional rounds equal to your intelligence modifier if your concentration is broken.

Ritualistic Boon

when summoning a demon using your dark ritual class feature, you can elect to give yourself a boon instead of giving an initial command. the demon is immediately banished, and you gain one of its abilities or actions. you keep this ability until you complete a long rest. while you have access to this ability or action, you gain appropriate mutations by the DM to represent the absorbed power. This could be claws or a tail if you took an attack, or a change in skin color for invisibility for instance. In any case you grow demonic horns during this transformation. you also appear to be a fiend and chaotic evil for the effects of spells, abilities and special senses. 

demonic lord

you are now an expert in the demonic arts, you automatically know the true name of any demon you summon. in addition, you now have advantage on saving throws against magic and other magical effects.