Day 4 is harder than Day 10.
The "smoke and sulfur" night destroys my base every time I play with the Sage. Even when I start my game trying to build up a good counter (like I thought the infantry rush perk would help, or improving my archer skill tree) they are so hard to hit, and so deadly against buildings, that they just annihilate my base. The only way I've made it through is if my crystal survives, I can rebuild the rest of my town. I think this is why under Steam Achievements it shows that 16% of players have beat the game as the Forgemaster (which has counters to them), but only 3% have beat it as the Sage (which does not).
Hey, sorry to start with a criticism. There's a lot I love about the game. The overall loop is great fun, and I love some of the details. The rare weapons are a nice touch, and I like the ability to get rare units like the shaman or golems. I also love the ending, after you beat the Lich. Very creepy.