Arcanum of Binding

Magi studying the Arcanum of Binding have focused their studies on the dangerous art of conjuration and summoning, learning to bind and control very dangerous beings to aid them in their goals.

Binding Arcana Spells

Level Spells
3rd find familiar, protection from evil and good
5th hold person, earthbind
9th summon lesser demons, magic circle
13th summon greater demon, banishment
17th infernal calling, hold monster

Elemental Familiar

In addition to the normal forms your familiar can take, you may choose any elemental of CR no greater than 1/4 by expending 1 point from your arcane pool as you summon it. Your familiars are able to take the Attack action; instead of acting on their own initiative count, they act immediately before your turn.

The elementals you may choose from increase in power as you gain levels:

Binder's Focus

At 6th level, you learn to focus more deeply on your spells - you are proficient at concentration saves. When you cast a concentration spell, you may pay 1 point from your arcane pool to give yourself advantage on concentration saves to maintain concentration on that spell.

Will of the Summoner

When you reach 11th level, you gain greater control over the creatures you summon. When you cast a spell which results in the summoning of demons, devils, or elementals, you gain further control over the summoned entities. When any such creature begins its turn, it must make a Charisma save against your Spell DC; if it fails, your direct its movement and actions completely for that turn. Afterwards, it believes that it decided on those actions itself, justifying them however it needs to.

Additionally, you learn to dismiss your summoned creatures - as an action, you may force one such creature to make a Charisma save with disadvantage - if it fails the save, it is returned to the plane from which it was summoned.

Double-Bind

At 15th level, your skill with binding spells allows you to split your focus. When you cast hold person, hold monster, earthbind, or banishment, you may pay 2 points from your arcane pool to target a second creature in range with the same spell.