There are rules. They're just not publically available to prevent metagaming, since once you figure out/realize the weaknesses of the disciplines, the disciplines suddenly become a lot worse than if you were to just do battle conventionally.I feel rules should be set in place to reign back the magic system. Because as it stands if I get creative I can effectively snub any threat with each of the disciplines (especially the healing one, enjoy a finger growing back in your heart.)
There should be a system of checks in place. Like taking a will check against cognimancy. This could lend to more professions popping up. Like enchantress and scribes. Making armour that counters magic by offering a boost to saves. Other boosts granted for things that go against a characters core. From simple things like most people will not kill themselves at a mere thought.
Ultimately however my main issue is with cognimancy as it takes control away from the player. When I can get into a fight. Then suddenly be told. Your character has fallen madly in love with mine. Enjoy your concubineship. Which sends extremely creepy vibes up my spine and latches to my neck.
This has turned into a bit of a rant but also the lore seems a bit lifted from magic the gathering. Intentional or not.
"The spark is triggered by a powerful, emotionally-affecting, perspective-altering life event, often a near death experience in which it triggers to protect the individual. Making them a planeswalker"
Feel free to argue against me. My main issue is the sheer potential of this.
For that matter, mastery in the magic system is not so much a straight upgrade, but more of a sidegrade. Mastery in it implies a great deal of skill in using and executing with it, but it's not much different from - if you were fighting them - a master warrior. There are some different tricks you'll need to counter, but assuming you come prepared, knowledgeable, and do not act uncautiously (like how you would also have to tackle a conventional warrior of this caliber if you wanted to have any chance of success) then you're fine.
There is no one discipline that operates off of scaling saves from other players; that's simply impossible to quantify. There also exists the matter of being able to outplay mages indirectly; like puzzle bosses in many games, you would have a hard time tackling them directly, but once you figure out what you're doing, it becomes easier.
Regarding Cogimency, that is something that is literally impossible to do within the discipline. Cogimency does not deal (directly) with emotions. The Cogimens could illusion themselves to look like your significant other and attempt to seduce you, but that's sort of hard given that that they can't capture all of the subtle nuances of another person, how they'd act, their voice, etc on the fly.
Regarding Magic the Gathering: I, nor anyone else who wrote the lore to my knowledge, have any experience in or knowledge of the lore of the franchise in the question. Any similarities are just a somewhat amusing coincidence. Given that there are probably thousands of magic systems out there, each relatively unique from one another, I'm not surprised there's the tiniest bit of overlap.
Finally, with creativity/potential, there's not really that much. Regarding occult pursuits, yes, there is a great deal that a mage could do to pursue something of this nature. I don't know what it would accomplish, though. If you had a good knowledge of physics, you could invent a lot of our modern conveniences if you were exceedingly clever. With alchemy, you can come up with poisons and cures that are otherwise unheard of in Altera. Now this doesn't matter if you're solely wanting to pursue something occult-y and magic-y, but it's the same way with someone who has no prior swordsmanship wanting to pursue a swordsman. Does that make sense?