Adding on to my last comment: In fact, all of these skills that give a fixed amount per level need to scale their reward to match the level of cost. Enemies scale up way too fast to still only be gaining 2 of a stat per level when you spend over a million TP in a skill.
The beinning of the game was slow.. but not too slow, the middle of the first area was a really good pace and was fun! But then once you get to that last area and try to start going into a new world the game comes to a screeching halt, being even slower than the very beginning. That is just tedious and I don't really see any skill that is going to speed this up except active skills. Relying on active skills instead of them being a boost to your speed is an idle no no.
The third tree needs a buff or a serious cost reduction. The level of gain vs cost on that tree is really lame. Like, health regen should be a percentage.. not a fixed amount. that will never scale well and will be worthless after a bit. You can spend several million TP in Health regen and not even have 1% of your health back a turn. That is ridiculous.
Great idle type game so far! I think it would be nice to have a skill for damage like fortify is for HP. I say that mainly because now that there are a lot more infinite skills in offense it makes offensive chance almost useless.
Hit streak works for archers, swords work for all classes for damage boost, and as far as I can tell multiple shot does NOT work for priests. Yes you can stack books for multiple hits/heals chance.
I think it would be cool if you had two different formation modes. One for normal mission time, and one for when the boss comes. That way you don't have to reposition everything all the time.
Epic Challenge 1 is a good way to make a LOT of money. Just position your troops just infront of your castle... and wait... keep meteor blasting the black ones as they come out... If you decide you want to win instead of surrendering (Loot money is where it's at anyway). Just build up your mana pool, then assault while keeping stop active... simple.
 "Immortal Hero Idle"){kind=icon}
 "The Perfect Tower"){kind=icon}
 "Idle Raiders"){kind=icon}
 "Kill the Plumber"){kind=icon}
 "Enigmata: Stellar War"){kind=icon}
 "Epic War 4"){kind=icon}