The example I gave is based on the character who invents the spell in question. The NPC has their full stats published in the book. I know you can get to some extreme lab totals if you put your mind to it, specialize and spend a few decades on it. It's just that the PC given does not seem to be in a position to do that. I could just hand-waive it, but I know my players and they would ask.
The Magic Realm trick would not work in this case, for reasons I won't go into. Aura of 10 is really the limit.
However, I am in the mood to tell a story about an NPC I ran who did just that. This is the story of Necrotus the Putrid of House Flambeau:
Necrotus was an NPC necromancer (major magical focus: Death) and follower of the school of Apromor (perdo). He was born and raised in Bavaria, but moved to Provancal after his gauntlet, joining the PCs covenant but generally keeping to himself. 15 or so years into the game he became annoyed at how Dominion auras kept cropping up whenever a few peasants set up a chapel, and decided that something had to be done! He disappeared into his lab, and did not emerge... for almost 20 years. The players literally forgot about him. Perhaps a full calendar year of real time later, and perhaps 30 or more sessions, when the covenant had it's annual meeting, Necrotus shows up, warped all to hell. Twilight scars positively dripping off him. I had been quietly updating his sheet each season, and he had been busy.
Necrotus announced he had developed a "Final Solution to the Church Problem". First, he had invented a new Hermetic Target, based on the "bloodline" target of fairy magic, called "Hierarchy". A spell with this target affects a individual, and all those who have sworn a binding oath of obedience or loyalty to them. It operates recursively, so for example if you cast it on a general you could potentially wipe out the whole army, since it would effect the captains sworn to him, and from them the men sworn to the captains. The effect does not hit those below someone who has sufficient magic resistance to resist the effect. He then developed an experimental spell of about level 75, which would slay (like clenched grip of the heart) at Arcane connection range, hierarchy target.
He had three requests:
- Provide enough perdo and corpus vis to cast the spell. (He was due this from the covenant stocks anyway, based on their charter)
- Assist him in casting the spell via Wizards Communion to ensure sufficient penetration.
- Help him acquire an arcane connection to the pope.
The PCs were speechless for about 30 seconds. They knew he could have killed them both with a thought (he was a master of "Clentched Grip", with a massive penetration score), so They played along for a couple of seasons, pretending to help... Then they straight up murdered him with an enchanted trap and told the rest of the tribunal that he died in a lab accident. They decided he represented an existential threat to the Order and themselves, and his mere existence in the covenant tempted the wrath of the Divine.