How can two disciplines of the same magic system be made incompatible?

Question

Daemons are malevolent spirits that inhabit the astral plane. This religion views these spirits as divine beings and worship them as gods. They are heavily revered in the faith, and are considered higher life-forms that are superior to humanity. Daemonology is the study of these creatures in order to use them for their power. This craft exists in two forms of study: The path of the summoner, and the path of the host. Both of these disciplines have their strengths and weaknesses, and are a reflection of daemonic society: that of constant improvement over one's self through ruthless individualism and subjugation of the weak. The only law is power, which must be used to acquire resources at the expense of the innocent. This is the only way to run a proper society.

The path of the summoner involves the torture and enslavement of daemons in order to bind them to the will of the practitioner, the practitioner can wear the daemon like a glove or a second skin. At this point, the daemons powers and abilities can be exploited, with the user calling upon them as needed. The daemon can even be summoned entirely, separating itself from the host to use its true power at the behest of its master. This path is multi-faceted, with users gaining access to the abilities of numerous daemons. Several creatures can be bound at once, with the most powerful users able to enslave dozens of daemons in this fashion.

The path of the host involves the same process of subjugating a daemon, but involves binding it to a user's soul, turning the practitioner into a daemonhost. This daemon-human hybrid is a demigod representing the best parts of mortal and divine. This path focuses on specialization, with the individual gaining access to one set of powers. However, those abilities grow with time, making the user more powerful.

Obviously the best goal that can be realized would be the combination of both paths. This would lead to a daemonhost that can control other daemons. This would be the ultimate dream for any practitioner, as it would lead to UNLIMITED POWAH. Sadly, this would be too OP, as the resulting being would kill everything on the map. However, no respectable student of the paths would shy away from achieving more powah for themselves, as not doing so would betray everything they stand for. The only way to prevent this is to design some way to prevent this from happening. How can this be made possible?

Answer 1

Freidrich Nietzsce's notoriously said

"And if you gaze long enough into an abyss, the abyss will gaze back into you."

That's precisely the reason: when a demonologist trespass a certain threshold they become the very subjects they want to subjugate.

Turning from being a master to another master's tool is nowhere appealing.

Answer 2

Daemon husbandry is a constant struggle.

The daemons aren't very fond of mere humans taming them. They try to resist domination. Daemonologists must keep deep concentration in order to subjugate the daemons and use their power.

Should a daemonologist get distracted, or lose focus for some reason, the daemon(s) would take over and do nasty things to them.

Having said that, it would be extremely dangerous for someone to try to follow both paths at once. But some overly greedy daemonologist might try... An interesting plot could rise from that.

Answer 3

/This would be the ultimate dream for any practitioner, as it would lead to unlimited powah. Sadly, this would be too OP, as the resulting being would kill everything on the map./

They leave the map.

Daemonhosts that can control other daemons lose their foothold on this plane and wind up in the astral plane with all the other daemons. Some are powerful enough that they can just barely maintain a presence in the material plane, but at the expense of being unable to do much more than be present.

In the astral plane these things are powerful indeed. There are also other powerful things in the astral plane. Some resent these outsiders showing up.

Answer 4

They're not incompatible, daemons can use daemon summoning.

Unfortunately, this means that demons can also use daemon summoning. If you bond with a daemon and become a daemon, then other daemons can summon you and will summon you for use in disputes, wars, pleasure and whatever they will.

Daemons you summon can also summon you and bind you, which makes bonding daemons notably harder.

Answer 5

Daemons are Sadomasochistic:

No one LIKES being enslaved, but let's face it - the astral plane is a brutal, torturous place where daemons constantly vie to dominate and control each other. No daemon lasts long as an independent entity unless they are really good at fighting off domination by other daemons and having the ego to resist them.

Humans, on the other hand, are timid, innocuous creatures and our world is like a quiet day in the park. The very reason humans are successful is they AREN'T daemons. There is a lure to domination in our world which is shameful but pleasurable.

While daemons don't WANT to be merged with a human host, they know that after a relatively cushy time on this world, the daemon returns to it's native realm as a hybrid being with a new human soul fused to it. The battle in the daemon is both with the suffering of torture, but also the gain in power the daemon gets in the long-term. Pleasure and pain merge and the daemon is swept up in the metaphorical moment.

Conversely, daemons summoned and dominated by wizards aren't REALLY under control. They have the spiritual equivalent of a safe word. The daemon can ALWAYS resist, but the release from the constant struggle with other daemons is so great that the daemons gain strength over time resting in our world. The humiliation of being controlled is outweighed by the pleasure of release from constant struggle. Rather than continue resisting, the daemons take the chance to be bound in our world, knowing they always can resist if things are really bad.

But a daemon will ALWAYS resist binding to another daemon. It's the central fact of their existence. So a daemonhost IS a daemon to all other daemons. There's no upside to domination by another daemon - no gain, no release. Nothing humans can do to a daemon measures up to being controlled by another daemon. So a human who becomes a daemonhost will immediately lose control of all their daemons, as being controlled by other daemons is worse than any mortal suffering, and daemonhosts can't summon more because the daemons will never surrender to another daemon.

Answer 6

We humans have the triad of Mind, Body, and Soul. It is the combination of all three of these things that make us the specific humans that we are.

It is well-known that daemons are stronger than us average humans, that is why we have to forcibly subjugate it to our will -- we have to prove our strength to them in ways that they will comprehend and grudgingly accept. Or not and we take their power -- either seems to work.

Binding a daemon to the body or the soul leaves the other two pieces untouched by the daemonic force. As such we retain a majority of what makes us human. Even the daemonhost, which becomes a demigod in power by taking a daemon into their soul directly, still has a mind and body that are human, that recall being human. In essence, those that bind daemons are human enough in the spiritual sense to continue down their chosen path.

Doing both leaves only the mind untouched by daemonic influence. That is two parts touched by and warped by the daemons and one that isn't. The instant one tries to follow the second path, the human has ceased being human enough to count for the first path. The three entities (two daemons and a human) cease being their individual selves and a new daemon is born from the fusion of all three beings. If the daemon bound to the body is lucky, they might get away severely injured and/or depleted when the reaction starts

Since it does not look like a daemon can be in the material world (easily?) without a host to hold it there, the new daemon is instantly yeeted from the mortal world and left to find its place in the daemonic hierarchy, to use or be used. If they recall their former life, they may actively look for a host to subvert, or viciously avoid becoming a pawn to the humans they once were.

Answer 7

They use the same resource.

The Demonhost binds their soul to a single demon. Conversely the Summoner binds the demons to (part of) their soul. Since you only have one soul of course you cannot do both at once.

Specifically the Summoner chops off pieces of their own soul and grafts them onto demons to give them control. While the Host chops off the entire soul of the demon and grafts it onto their own soul.

So why not do both? Graft half of your soul onto some Summons and then use the other half to Host a demon? Unfortunately this will result in the demon's full soul taking over you instead of the other way around. . . .

. . . at least using any of the demons anyone is interested in hosting. It is possible to Host a Quasit or Millipede type demon using only half of a soul. But those guys are so small and puny, this makes you weaker than a baseline human. Anything worth Hosting required your entire soul.

The finite resource means you cannot be both a powerful Summoner and Host at the same time. You can only be a half-decent Summoner and half-decent Host.

Answer 8

The method of control allows them to disrupt each other

Path of the Summoner relies on subjugation and is a method in which you hold absolute power over the subjugated. The daemons can scheme all they like to try and get a summoner to relinquish their power but, it is a one way transaction of power. That is why summoners can control many daemons.

Path of the Host relies on subjugation of a single demon and binding it to you so completely that it merges with your very soul providing proof of your dominance for the entirety of your existence.

However, the daemon of a host can still fight back. It is inevitable to lose to its host as it is weaker than the host. After all, it was subjugated and so most daemons don't fight back. The host cannot put other daemons on the leash of a Path of the Summoner because the disruption of a hosted daemon fighting back gives all the subjugated daemons time to act without fear of retribution as the host wages battle. This often ends in the summoned daemons killing the host to be set free.