A little background:
So, my world is a large world which has 5 intelligent races which are : elves, orcs, dwarfs, goblins and humans of course.
Humans are, well ... as we know them. They are largely separated between different kingdoms (5 actually), but in the continent where I'm setting the story, there are only 3. Humans main strength are specializing as warriors- they still have a wizards but not many of them. Of course human rulers are kings, dutches, etc.
Elves, are similar to humans but theirs society is much more bigger; I mean, they have fewer kingdoms, cities and provinces but the population in them are much, much higher compared to human kingdoms. Elves also are separated by two large groups, the Highborns and the Second Bloods. Second Bloods also include goblins and a race of dwarfs that are kind of slave (I mean kind of because it's not like they have them tied up doing their chores but their race does serve the Highborns). Second Bloods have one leader per race, making a council. Highborns have a king and a council comprised of important people. Elves main forces are mage warriors. Elves discovered magic and evolve it, but (I will explain this in a little bit) their warriors are not 100% magic focused, they just use some to defend themselves.
Information about other races will be provided if needed.
Also, only a few wizards go back to their kingdoms after being in The college of wizards, and they usually return as a councilor as well as training a few soldiers with a little magic usage so they are not defenseless against a few magic opponents.
**A legendary story of a long time ago **
(Resumed cause this post it's getting to long already)
There is a legend about my world, when the civilizations were young, kingdoms as we know it didn't exist. War was always present especially between races. Humans were barely able to control a bit of magic, during their fights against elves they would capture them and study their magic, trying to learn it.
One day they captured a powerful elf mage, who has studied forbidden magic, and the man refused to teach magic to such an ignorant race so when the humans tortured him he opened a portal to let a horrible creature into this world to get vengeance upon the humans. The creature he summoned was a demon who wanted to invade our world. Incredibly fast, the demons swarmed the world and all life-forms were threaten.
After failing at making the demons fall back, all races united into an enormous army and then angels came down from the sky and gave the non-demon armies holy items to fight against the army of demons.
Eventually they won.
A megalomaniac human mage wants to dominate the world by using the power of blood magic (term used to refer to demon-involved magic), and summoning demons into the world.
Now, a large group of Second Bloods will follow this lunatic wizard, because he deceives them by making them believe that he will free them from the highborns (and yeah, he will help them with that but that's not the long term plan).
But how do I make a large group of humans follow him? Other powerful mages won't follow him, as blood magic is forbidden and is only studied by archmages, only for the pursuit of knowledge, maybe a few magic-users, like healers or few soldiers who are able to use magic.
Mind control is off the table as it doesn't really work on everyone and other mages can see through it.
Edit: our little mage has to work in the shadows because otherwise he would be hunted down. It's a great risk that he cannot afford, if the wizard college figures out what he is doing they will personally intervene.
A megalomaniac wizard wants to dominate the world by the use of magic, related to demons. He wants to summon them into our world. He had already deceived a group of elves by making them believe he will free them from their rulers.
How can I make him convince a group of humans to follow him in his mission of conquesring ... Well, first the kingdom- and then the whole world?
PS: Sorry If bad English! I hope you are able to understand everything, if not I'll edit.