New order.

The second one is still an absurdly strong opponent. The added garrison slightly improved the situation – the first attack occurred around the 2nd week, and the first mage was severely damaged, but the garrison didn't stop him. It's now the 4th week. I've already thrown 5 Colossi, 5 Rakshasa, 20+ Djinn/Mages, 50 Golems, a hundred Gargoyles, and three hundred Gremlins at him. The garrison also has another mage with 2 Titans left, https://c2n.me/4cEInV6. Where does he get all this meat? I have a hundred Gremlins and two dozen Gargoyles left. I can buy another 20-40 Golems, but they're basically useless. I had enough money to build, but not enough troops. Maybe I should increase the garrison's strength by 5-10 times so it can hold out for a decent amount of time? I even ventured out and took 3 mines, but he has them now. I need to sit back and defend. And it's not like he has a decent mage hero; he's just terrible. He has Herbalism and one arrow in his spellbook, and useless Sorcery takes up 4 slots. It doesn't prevent machines from falling, and Mentoring is somewhere far away. He has zero special abilities. The Demon is also struggling underground; he cleared out a bit, but his Fire Arrows are blocked by a starting skill.

Added 23 minutes ago
A couple of in-game days have passed since then, and he already has several Titans, several yellow Rakshasa, a group of Djinn, many Mages and Golems, and a horde of Gargoyles. I've already destroyed a ton of his units, and he still has more, and they're even upgraded, and it's only the 4th week, 3rd day. I have 160 Gremlins, 28 Gargoyles, 60 unupgraded Golems, and a useless hero. Not a great situation.

Added 14 minutes ago
And the extra fun is that a mine is located behind the garrison, so building is difficult...