The basic idea here is solid and I'd love to see you develop it further, but as it stands the user experience is just absolutely nightmareish.

Mostly, the amount of detailed management for each hero would be suitable for an RPG where you have maybe eight characters, at most, being recruited and slowly developing over many hours of playtime. It's not at all suitable for hordes of largely interchangable generic units where you get swamped with a pile of procedurally generated items.

The skill tree is also completely overwhelming, with a huge number of possible paths and the implication of strategic party design that feels out of place in a fire-and-forget battle system, presented in a confusing and hard-to-parse way, and on top of all that it it looks like SP are non-refundable so you have to commit to a whole bunch of stuff with the prospect of losing some amount of progress if you change your mind, and do so before you have any idea what any of this stuff means.

The UI for equipment is also just kind of terrible, made worse by the fact that even identically-named items seem to have wildly varying stat bonuses, so you can't even just easily say "oh this is a better armor type I'll start equipping it on all my warriors", no, the stats are all over the place and you have to constantly juggle a bunch of dropdowns and modals to go through an entire party's worth of equipment. And if you have auto-run going, by the time you finish there's probably a new pile of loot that may or may not be better than what you just equipped.

Generally, it suffers from a click-heavy deluge of trivial decisions where there isn't a clear best option but that not making the choice immediately is obviously the worst choice. It feelsl ike busywork.

A few concrete suggestions:

• Ditch the procedural equipment. If you like the idea too much to lose it entirely, limit it only to high-rarity artifacts and ideally use procedural names as well to make it clear that they are unique items.
• Either make the heroes completely generic such that dismissing and replacing them is trivial, or make them effectively permanent with options to re-do the build. e.g., sacrifice a level to reset the skill tree, a full prestige option to restart the hero with some sort of bonus, etc.
• Make the skill tree class-specific and/or get rid of most of the "handful of bonus stats" nodes. Focus on things like the "Keystone" nodes where it makes a significant impact on how the hero fights. Make them cost multiple SP as needed to balance overall level progression.

In general, I'd suggest studying existing dungeon crawler games and liberally taking inspiration from how they handle similar ideas. In particular, the Etrian Odyssey games have a similar concept of managing a guild made of customizable generic units.