akashic said:
Couldn't a wizard like Thoth-amon invade some regions by his own? And how about defeating an army on his own?
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By "on his own" you mean literally on his own, singlehanded? Not likely I think. This isn't DnD, the concept of a "battle mage" is foregin to Conan. Oh sure, sorcorers show up on battlefields all the time and often their success or defeat (at the hands of steely thewed heroes, natch) is responsible for turning the tide of a battle (the story
hour of the Dragon has some good examples of this). But they still need an allied army to protect them as well as do the actual dirty work of conquest and subgation. Wizards can change the course of history by showing up in the right place at the right time but they can't be everywhere at once and even with spells like "Black Plague" they can't actually defeat an army without having at least the threat of their own army to send after the survivors/invade the emeny's own lands. The old saying is that "it doesn't matter how powerful the wizard is; a dagger in the back is still a dagger in the back". Conan highlights this pardagrim.
If a sorcorer did want to take over a kingdom "single handed" he would be more likely to either A) impress/intimidate one small settlement into obeying him then use them to attack/absorb their neighbors until the whole thing snowballs into him becomming the ruler of the region (AKA: the "Man Who Would Be King" scenario) or B) locate the key power figures and lie/cajole/bribe/blackmail/intimidate/manipulate/enchant/mentally dominate until he becomes the power behind the throne (AKA: the "Jaffar" scenario) or else C) assuming some kind of sorcous coven/priesthood already exists join them and scheme/backstab your way to the top so that you rule the general region by default of ruling the state religion/worst group of badass magical mo-fo's present (AKA: the "Thoth-Amon" scenario) or finally D) make enough demonic pacts with enough nasty nasty nasties until you can finally work your way up to summoning a Great Old One to eat all your enemies for you and allow you to rule over the blasted landscape for three whole glorious seconds before he eats you too (AKA: the "Sweet Baby Buddaha's Left Nut! He's Gone Mad" scenario).
Scholars in Conan are particularly good at scenario A (required styles: Curses, Nature Magic, Prestidigation) and scenario B (required styles: Hypnotism, Divination) though any scenario is possible and will make for a great story.