How can daemonic pacts made across different realities be honored?

Question

Our world orders the immaterial realm, a place in which daemons and otherworldly creatures reside. These separate realms have their own rules governing their realities, such as gravity, physics, and the laws of magic. However, there are certain places in which these worlds overlap and intersect with each other. Within these places, transmutation circles can serve as a gateway between worlds, allowing one to communicate with beings on the other side. A transmutation circle is a sigil or sign for a specific magical purpose, combining a complex combination of symbols and text to perform spells and rituals. When the proper requirements have been met, a mage can activate the circle using his own mana as a power source to fuel the spell. This opens up a connection with the immaterial to create a gateway linking both worlds. This gateway operates as a small pocket dimension that exists within the material world as its own pocket of reality. Within this reality bubble, mages can summon daemons and bargain with them in daemonic pacts to gain powers. The daemon within cannot cross the border of the circle, keeping the user safe from any danger posed by the creature.

Powers given by daemons take the form of boons, powers granted by deities to mages that are meant to be beneficial in return for service to said deity. They can take the form of specific powers or access to magical spells unique to the deity. Daemons grant these boons to their followers to pursue goals on their behalf on the mortal realm, or as a gift in return for some service performed by the mortal in the hope of future cooperation. However, as the spell is only fueled by the mage's mana, it can only last for so long until the gate has closed. once the spell has ended and the connection between both realms is broken, the daemon is sent back to the immaterial. As the rules of host reality reassert itself, the power that the daemon had to influence the mortal world is lost. Any boon given to a mage should be rendered null and void due to it being incompatible with the material verse.

How can a mage continue to use their newfound abilities when the daemon is no longer able to reinforce their end of the bargain?

Answer 1

Magical Focus

A common element of mage-craft is the use of a Focus. This typically takes the form of a Crystal Ball, or a wand, or a staff.

The form doesn't really matter that much, essentially it's an item the magic-user draws power from or casts their own power through for greater precision or potency.

In your world, the Focus is created specifically to act as a physical link between the Daemon (in its source of power) and the Mage's world.

You could think of it as a Transmutation Circle in a portable format.

So by this pattern, the Mage's bargain with the Daemon is essentially an exchange of contact information and an agreement of terms and conditions.

The Daemon ritually links themselves to the Focus in an intimate way that provides the Mage with access to their power. Perhaps by sharing some or all of their True Name.

Once that task is complete, the Daemon can go back to its own realm and the Mage can call upon their power whenever they choose via the Focus.

Answer 2

Instantaneous Magic

Demon Booms work by temporarily changing the rules for reality. For example a Demon alters reality around someone so that injuries heal much faster. The target's mangled arm quickly heals into a working arm. The Demon then leaves and reality reverts to normal.

Does the arm go back to the mangled form? Nope, why would it? Now it is just a normal healthy (nonmagical) arm, and the usual rules of reality allow those.

The demon changes reality so that centipedes are spontaneously generated. Loads of bugs appear. The Demon then leaves. Do the bugs leave? Nope, they are just plain ol' nonmagical bugs. The only magic was the magic that brought them here.

The demon changes reality so that a piano appears above my head. I go splat. The Demon then leaves. Do I get better? Nope. Now I am just a splatted person.

The demon changes reality to increase the size of the mana resevoir in Gerard's head. Gerard can now hold twice as much mana. The demon then leaves. Does Gerard go back to normal? Nope, this is similar to the arm example. The mana resevoir is not itself magical.

All demon boons work like this. They create changes. They do not create continuous effects.

Answer 3

Devil's mark

In folklore daemons often take souls in return for the powers they give, I understand that in your universe servitude is the price of those abilities, but maybe daemons take some part of the mage as a collateral. This part stays in possession of the daemon in a neighbouring realm making the mage into a kind of strained Reality Intersection, which allows daemon to keep tabs on the mage and give them it's power.

This could also allow other people to recognize if the mage made a pact with a daemon, because reality could slightly break around this person i.e. they would be affected by a mix of rules from both realities they exist in, maybe they would cast shadow towards sources of light or everything would be lighter around them, depending on what rules apply in daemon's reality. This would be titular Devil's Mark. Hope i helped.

Answer 4

Brand the mage with a 2-way transmutation circle to seal the pact

While the transmutation circle created to summon the demon is one-way and in the total control of the mage, this second transmutation circle can be opened by either the demon or the mage using either one of thier powers, and it is forever burned into the flesh of the mage so that it can not be easily removed. This way, the mage can open the link whenever he needs to access the demon's power, but the demon can open the link whenever he needs to check up on the mage to make sure the mage is honoring his part of the deal.

If the demon ever opens the link to see the mage is not honoring the deal, he can use the link as a conduit to project his power through to punish the mage. Since part of the question is about enforcing the contract, the demon has a vested interest in NOT giving the mage a transmutation circle that can just be thrown away when the contract stops being in the mage's best interest. By making it a part of the mage's body, the demon is guaranteed oversight over the deal.

As a side note: 4dam's Devil's Mark answer has some very good ideas about stuff you can do to make a branded character more interesting, even if it does not actually answer the core of the question about how to make the contract enforceable across realties. If it were me, I would work some of those ideas into this such that the mage might be able to figure out when the demon is watching when the laws of nature around him start to subtly shift.

Answer 5

Have cults to power them.

When the magic runs out, the gift dies. As such, never let the magic die.

Any magician who summons a daemon will make sure to have a group of fellow mages and cultists to back them. They can use their shared mana pool to sustain the gift long enough to enact whatever wills they have. While communing across dimensions is immensely hard, powering a spell is much easier and relatively low skill people can be used to fuel it.

Daemons will need to carefully select their gifts to be within the ability of the mages to supply enough power. Too large a gift will quickly drain the cult dry. Some daemons also engage in parasitism, adding secret spells to their main one that consume some power to enact their will or gather up power for future communions.

Answer 6

Ever read the Discworld series of books? There are tons of material on demonology there.

Some songs were made for the books, and one of them has this in the lyrics:

The staff of a wizard can hold many spells
For finding lost objects and dowsing new wells
For banishing demons to bottomless hells
And bringing them back on demand
And bringing them back on demand

I think the last couple verses are what you're looking for. Alternatively never banish the little bugger, just keep it in a jar.

Answer 7

In fact, daemons provide something that cost nothing in their world. Same for mages: they give mana (which will be restored in couple hours) and get something special.
The real problem is to connect each other. That's your transmutation circles are actually do - like online marketplaces connect customers and freelancers.
Circles are designed for immediate contracts but hey - you could want to work outside this 'magical Upwork' (to cut off intermediary's expenses and expedition costs). It will break the rules - but who cares? You agreed with daemon that when you send some energy to that special amulet the daemon would decrease the gravity around it.
Of course, such amulets also breaks the rules (some legal, couple physical and dozen of magical) but again - who cares? Actually, this amulet is just better version of transmutation circle.
Who crafted it and why the Mages Guild conceal fact that it's possible to connect with daemons without circle - this is a good story for Part 2. In Part 2 you'll also know about those 'who cares' and what they do if catch cheater.

The idea was borrowed from short story (original is in Russian. Probably automatic translate would be good enough. Disclaimer: I'm not author of this story.)