Having cleared the game on normal. And idiotically being curious about the unlockable abilities of the units. I can give you guys a few tips.
1). Buy the upgrade that allows you to lock a unit as soon as possible from the merchant. Who occasionally pops up after a battle. You can lock an evolution and it'll be among the free choices at the end of the turn in a battle.
2). Buy as many units preferably filling the formation you intent to use throughout the battle before evolving. They get more expensive afterwards.
Having frozen the evolution upgrade. You can even wait until the end of the next turn where you receive a large amount cash. Be quick or you'll lose the free upgrade. Having 2-3 columns of the target unit before evolving will save you around 200-300 in cash.
3). You don't really need health on your ranged units, so don't make that a focus. Unless you foolishly also only take health upgrades during a battle. Even then you are likely to be one shot by most abilities of the bosses/mini-bosses.
4). The two sword units (the woman and the ghost samurai) both have too little health to be on the front imo. in the late game. They'll likely be sniped too. So ignore them for upgrade and gameplay purposes.
5). The wolf/panda thing is really good against most bosses when fully unlocked. I think it has some the highest dps and it'll also get a bit of armor piercing/resistance reduction.
6). Use traps. They won't be destroyed by the abilities of the bosses and they recharge. They are NOT a one time use thing. Have a screen of around 3-4 columns of traps.
I've come to prefer the firefly trap. It's cheap for a trap and the last tier unlock gives it a 1000% damage increase. While the speed is reduced drastically... the speed upgrades you get doing battle seems to affect this unit a lot more percentagewise. The first speed upgrade has it going from 18secs to 13 secs. The damage upgrades also gets quite hefty on this unit, but it doesn't show that much on the first few of them. The fire flower trap might have a similar attack value and a faster attack rate. It ends up being almost the same, if you fully upgrade the attack rate of them during battle. The firefly is, however, ranged meaning it counters a certain type of mob which can destroy traps (and everything else) and it's cheaper.
The demon rift is an expensive joke and the ice trap is not much to write home about. I admit, I could have missed something with the ice trap. It just doesn't seem to work on bosses.
7). The eye unit gets a power debuff when it evolves. What is not described is how it and the phoenix also gets more projectiles. Though the phoenix also gets a buff instead of a nerf to damage upon evolving. The eye unit is a solid unit when fully unlocked, where it gets a +300% damage boost. The wolf unit still out DPS's this unit, but the eye unit works well agains the walls and it's cheaper. Taking both in the deck is a waste, as they fill the same role. Cluttering your upgrade choices during battle.
I've used the eye unit a lot. I ended up going back to the wolf unit since it helps a lot in boss battles. The phoenix is able to get those annoying ginseng units and is overall better than the ghost tongue. Sadly it all too quickly gets overshadowed by the lightning fox.
8). The kekkai/"paper in forcefield" unit that you start with is one of the few units that can take a lot of hits from most boss abilities. In some of the boss battles it's an outright priority to get the health upgrades on this bad boy. The damage reflection is too little to be noticable, instead focus on making it do what it does best. Take hits. The 20% damage reduction is really useful in that aspect. Cheap, easily replaceable, and tanky. Keeps your other units safe. Can also save your skin from a bad turn 1.
9). The lightning fox is the only unit that can deal with flyers. She's also really strong. Fully unlocked her DPS is close to that of the wolf if you account for the crit, but it's of a different element. I advice taking both in your deck.
