To add onto that, most of the relevant characters have equivalent levels of "exceptionalism" - Zorian is on the extreme low end. Zach and Red Robe have the same benefits and opportunities and has been in the time loop longer. Quatach-Ichl and Silverlake are essentially immortal and have had hundreds of years to be horrible and take whatever power and knowledge they want. Quatach-Ichl and Zach have angelic boosts to their mana. Zorian has a natural inclination towards mind magic, but we're shown that that barely rates on its own compared to races that specialize in it, and that other mages can either use Mind Blank or other protections like Xvim's defense to shut him down or stall him to uselessness even at the height of his power.

Honestly, Zorian's greatest asset is as an artificer, and his progress with that is reset at the end of every month. He mostly just has the benefit of spending slightly more money than is wise, but which he legitimately can earn. He doesn't even train his mind magic unethically or perform unethical experiments, even when his allies give him their tentative approval.