The General arrives with 350 demonesses, 1000 imps (what a nuisance!), and other units, with an overpowered ability that allows him to spawn demons instantly, with expert-level Dark Magic and Machines skills.
This is against my 11 titans and 500 gremlins and other units.
I could only complete it on Veteran difficulty, and even then, I had to delay the General for several weeks using a cheat that the author suggested.
But there were some interesting parts.