Graaannnnd Magus!

Michael lets out a sigh at the weak insult and shrugs his shoulders, "I'm here to learn from you... And to explain your circumstances... Why you're here, stuck in this fake world."

...

"Fake. World...?" Rubick asks as if he hadn't noticed any changes at all.

...

"Yeah... Did you not notice the lack of any creatures outside? The inability to go a few miles in either direction? Or the unnatural ever-present lightning storm constantly raging overhead?" Michael inquires.

...

"No... I just thought that my methods of isolating myself were working. Ah, and the thunderstorm is of my doing. I found that no one wishes to visit during such weather, keeps the insects away too." Rubick adds as if summoning a thunderstorm was just a second thought to him. "Hmph, as you will. Follow the doors so we can speak. Oh! And don't spoil anything, I want to see if I can find my own way through this mystery..." he says, his voice cutting out as a door materialises at one side of the hall.

Michael begins moving, quickly realising that the insides of the tower didn't match its exterior dimensions. "It's bigger on the inside!" as many a Doctor Who companion will commiserate with. Yet another magic he needed to learn, especially since his own tower would be built relatively soon. Being able to expand its interior space would be incredibly useful.

"So, we are trapped in a suspended Dimensional Rift... Interesting... But what of Trigaraxxus' Theorum...? Oooh, it inverts like... This?" Rubick asks and does something which causes the very air to ripple and crackle as if the world the Grand Magus was held in was beginning to destabilize. The phenomenon ceases not long afterwards however, causing the feeling of vertigo Michael was experiencing to dissipate with it.

"Uh-hahauhaahuahhahauaha! Marvellous! The reaction was only half effective, meaning this place had a Divine origin!... Curious how they would create a replica of my tower, does the being responsible lack originality?"

...

Michael continues listening to Rubick as he walks through the increasingly bizarre rooms of the tower. Eventually coming out into a room that appeared to be at the top of it... Weird considering he didn't remember climbing any stairs...

Over at the side of the room, he spotted Rubick at some sort of drawing board working away while creating extremely complicated diagrams of god knows what. He observes it for a minute or two, not wishing to interrupt the powerful and probably crazy wizard, only to be confused when the paper he was using is turned completely black with ink. Rubick had created so many diagrams over each other that they'd all disappeared under each other...

"Isn't that a waste?" he can't help but ask as he cautiously walks over.

Rubick pauses and turns to face Michael, revealing his strange appearance. He was a thin robed man with bright glowing green eyes that shone through the strange mask he was wearing. His robes were elaborate and luxurious and shone with green magical energy that pulsed as if timed with the Magus' breathing. A staff was positioned next to the drawing table, the middle and bottom parts looked normal, but the top looked like the inside of a green lava lamp, the strange magical fluid flowing with no focus.

"Waste? Only if you lack the eyes to understand it. A beginner such as yourself would be troubled understanding the most basic magic circle, let alone the world-shaking realisations I am crafting... Still, I believe I know the situation, but why don't you illuminate it for me." he asks, pulling the paper into his hands as if he were a teacher holding a cheat sheet to a test.

Michael nods, "Alright... Well, right now you're inside a book-" he goes on to explain the situation to Rubick for the Nth time. Maybe creating some pamphlets for his Spirits wouldn't be the worst idea?...

The entire time he spoke however, Rubick was tapping parts of the paper and nodding, as if patting himself on the back for a correct answer. That wasn't wrong either, because once Michael finished, Rubick turned it around and revealed all of the important points already written on it.

"The destruction of my universe... You accomplished your goal, but why did you do this, hmm?" Rubick mutters to himself.

"You know who did this? I have some guesses but, it sounds like you've already got everything figured out." Michael asks.

Rubick nods, "I do. But telling you would ruin the mystery. A wizard with no goal in mind is just a desk jockey!"

...

"Let me guess, the Dead God?" Michael asks, knowing that said god was responsible for most of the Spirit's deaths. Not Rubick's though, apparently.

"Indeed. Gloomy fellow always for the finite to finish. How he accomplished what he did with this... 'Book', I still haven't determined... But, that is for later, for now you wished to... Learn from me?" he asks, his voice deepening as he does so, becoming almost hostile in its tone.

"Yeah." Micahel confirms, trying not to flinch at the Magus' sudden change in temperament.

Rubick tosses the ink-covered page away and is uncaring when it bursts into flames. "Why, and what could I possibly gain from it?"

Michael nods, already knowing what he could trade. The magic obsessed Magus should be interested in the possibilities he presents. "Access to magic from the multiverse. In fact, I already have three entirely different examples of otherworldly magic... As for why I want to learn? To put it simply, power. I don't care about understanding the universe, the laws of magic, or anything like that. I just need enough power to be able to punt a Demon God in the balls and not instantly die afterwards."

...

"Hmmm. Perhaps we could come to an agreement. I have many concessions however..."