Then the demons play along until it suits their needs at which point they lawyer up on the caster and do only the absolute minimum to satisfy the letter of every request and subjugate it when possible. Once the abyssal manifest zone comes along the demons now control the world and the ones not under direct control of the wizard show him their version of gratitude by having him tortured to death by their best guy.Continuously summon demons via Summon Greater Demon and keep them on the plane with planar binding. When you can congregate enough of them in once place you will create a demoncyst or an abyssal manifest zone and if you prevent paladins, heroes, clerics, etc from closing it you will usher in a planar breach to the Abyss and the eventual doom of the world.
There was a fairly specific set of circumstances that allowed the Nazis’s to rise to power - for a relatively short period of time - that caused the rest of the world (for the most part) to rise against them. That had little to do with a single person, no matter how charismatic.Look at how people have come to power in real life. Then imagine if Hitler and his henchmen had even basic spells like charm person, mass suggestion, etc available to them? "Dear Yamamoto, it would not be in your best interests to bomb Pearl Harbor and bring the Americans into this war." "Mr. (Hitler waves his sith hand)
You can already achieve a lot of power as a normal person with a decent charisma stat, so you would be extremely powerful just by slyly augmenting that with charming spells. Especially as a sorcerer with subtle spell. You wouldn't need to be a juggernaut yourself, but you'd have all the power at your disposal.
They didn’t take over the world. Most absolutist rulers had very little widespread influence without the support of others. Casting a couple of spells a day doesn’t change this.possible? Sure, IRL people become emperor without any magic to help.
a being that succeed all important ability check can become the leader of the world without magic!