This is going to need some serious balancing and tuning. The spawn rate in the second mission is overtuned. Olivia has 28hp, she usually gets hit every single fight, so you have somewhere between 14-28 rounds to finish the stage, that isn't a lot. Meanwhile, you control team baby that is weak af and can't take more than 3 hits without dying, aside from Beatrix, but she gets wrecked by magic. It's not looking good, when every single enemy takes 2 rounds on average to kill and there are 14 of them, with reinforcements from the throne room.
Next the weapons degrade per hit. There are also weapon abilities that take 3-5 durability per use and there is no way to repair that I've seen so far. I haven't seen past the second mission, so I have no clue if a store even exists to buy better gear, or repair. Also, random stat gains when you level can really screw you over. At the very least some stats should be guaranteed for each character based on their class/role, so you don't get screwed by bad rng. Like the priestess should get magic every level up so her heals get better and the prince should get strength, or hp on level up and then give them a chance to get other stats.
Another thing I noticed is do weapon types mean anything? Is it like fire emblem, where certain weapon types are supposed to go against others, or if you use the wrong type it will put you at a disadvantage? If yes, it should be in some sort of tutorial. I like the ideas and it seems pretty interesting, just needs some adjustments so people don't get their shit kicked in on the first stage after the prologue.