I see that the path of cheese is the true path and that one I'll follow but for now, I'm a scrub a-- since I'm trynna figure out how to not suck a--
The secret to not sucking, for me, was two fold, but one of them was kind of counter intuitive for me.
First, figure out what you can completely ignore, like all of the resources. My brain didn't like this at first, but it really was the most useful thing I've learned. Basically, the only things I would do that weren't focused on the next point was tavern quests, primary targeting circular resource trading, and a daily brothel show when you need money (it's giving me like 9000g per show in my current game)
And then 100% focusing on gene boosting spirits and seeds. For Evo, IIRC there's two nodes that boost your spirit's base stats, up to the point where you're getting 8 or 9 of multiple stats on spawning. Combining these into a single unit can get you a maxed out unit really quickly. Even a single point or two into the gene boosting stat will give you significantly strong units on your side. Then just use the arena training to get them to like, level 5-8, and you can start working on cheese. Under leveled characters with high base gene stats seem to be more useful than high level characters with shit stats.
It took a bit of luck to get the right species combos in the tavern and in the early maps to boost those gene stats, but once you start boosting them you snowball quickly. Then it's just a matter of hunting what you need, ritual-ing them, and tossing them in the brothel for passive money to afford the next one.
Then you just need some easy ways to snowball out of control. Like, more so than having maxed out units, which is already snowballed like crazy. The 'secret ending' NPC is super strong, from my experience, and with her leveled up a bit I was able to knock down kitsune bosses without much trouble. She does good damage, but she's also a great chase champion as she can teleport herself and your DPS to the boss.
And speaking of teleport, the teleport skill is super useful in unexpected ways as you can teleport into map tiles that you can't travel to. Not like, land to land, but like, land to tiles you shouldn't be able to teleport to. Want to clear hives from a sky map? You can apparently teleport into empty sky tiles. Just make sure you have enough crystals to reach the next set of land because you won't be able to move lol
My current game's party is four maxed out kitsune, and I almost never need more than two of them and a single round. I just wish I didn't set the game length as long as I did, because now all I'm doing is cheesing the broodqueen to keep rival strength down and hunting hives non-stop. I really think it's impossible to keep Sienna's corruption low on long games. There's just not enough portals where you can talk her back. She's at 8 power, and 75 corruptions
So far this setup seems easily strong enough to carry me through 100% difficulty. I'm just going to push for beating the 10 NG+ runs to unlock that cheesy god mode and then I'll unlock everything else.