Conjuration Branch

Throughout history, humans have used entities of other worlds to do their bidding. What better way to ruin your rival than to have Fey play tricks on them? Send demons to destroy the souls of your enemies, while you enjoy the carnal pleasures from Nysea.
At least, these are often the expectations held by those still naïve to how the world works. The fey will find it much more amusing to make life worse for you than your rival through the same actions. The demons will tear you apart for your insolence, and you will be lost to the world, thanks to the denizens of Nysea. Whatever you conjure, the consequences are likely to be more dire than you can imagine.

Reaching Beyond

In order to call on anything, a performer of the arcane has to adhere to a Tradition that can provide a link to very specific kinds of beings. Demonology can reach Inferno, but would have a hard time bringing the dead out of the grasp of Osiris, for instance. To reach any individual entity requires even more specific links.
Some summoning rituals include ways to control the summoned entity, but most do not. It doesn't help that there are rituals said to provide control but lie in order to prevent anyone from researching actually effective control.

Banishing

Expelling an entity from a plane is about reaching for the same branch of the Thorns as conjuring. Some of those who perform exorcisms would prefer not to think about it, but they use the same energies as those who would call on the outside force to begin with.
Conjurers lucky, or unlucky, enough to live long usually give the advice that one should always learn to banish first. Whatever you call on, it is likely going to turn on you if it can, and being ableto throw it back might be your best defence. It might even be your only defence - or hope.

Thorns

When the Conjuration branch is being pulled harder than the performer can control it, the Thorns pierce through the barriers between worlds. A best case sccenario might twist the building the arcanist was in to become a piece of Inferno on Earth. Entities from one or more worlds might appear and try to drag the culprit bach through the rifts in reality to where they can disect and understand them.

Common Traditions
Demonology
Hermetic Magic
Thaumaturgy
Voodoo

Type

Metaphysical, Arcane