Okay, I've finished my second run and examined most of the skills and builds. Fortunately, it seems the balance problems don't run as deep as I thought.
It's a little hard to decide where to start, so let me begin by showing a functional but unoptimized endgame build I think is balanced. This will be our "control group".
Argenta:
Has all Enchant skills. All Boost points in Wisdom. No Tempering.
Huntress Edge / Red Hood / Magus Robe / Adventurer's Mantle
Rose Tear / Book of Thieves III / ProRing / Red Shoes
Mu:
Has all Spear skills and Asura passives. All Boost points in Strength. No Tempering.
Highwind Lance / Red Hood / Survival Vest / Adventurer's Mantle
Asura Armlet / Lucky Coin / Nemesis
At level 30ish, these two can clear random battles in Ryuko Cave in two rounds, but they can take a lot of damage and are susceptible to status. That's a pretty good benchmark for an offensive-minded build. So, I think the core gameplay is balanced.
So, with that matter simplified, it's easier to pick out the exact things that go over the edge. Here is a comprehensive list of my major balance concerns:
1) Tempering is broken.
As you get further into the game it becomes easy to mass a large number of items to Temper with. They're mostly innocuous on their own, but you eventually have so many slots to work with that the bonuses start getting enormous. If you're wearing three items that can be Tempered, that's 15 x 5~10% boosts to all sorts of things. It's easy to get things like 25% HP regen / evasion / crit, if you're dedicated you can get way more than that. You eventually wind up with so much elemental defense, evasion, regeneration, etc that nothing can break you outside extreme status fucking. Then there's the ones that give you like 20% to all stats, and you can get multiples of them...etc etc.
I think it would be wise to limit Tempering to only one equipment type - I think a nice idea would be to give Mu a necklace and have those be the designated Temper items. 5 slots max with Tempering items giving 10% to one stat / 5% to two, or a resistance, would be reasonable. If you can change the number of slots different items give, giving special weapons or armor
one extra slot would be okay.
2) Pilfering gets you really overpowered equipment.
The items you can pilfer from regular enemies are frequently 2 tiers above whatever you can buy in the shops. A good example are the robes you can steal in the prison. You can trivialize a lot of the early/mid game this way.
But aside from getting equips much sooner than you should, some pilfered items are just totally broken.
- Magician's Eye, Rose Quartz: anything that doubles your damage really shouldn't exist, regardless of the drawbacks. Meguka Argenta doesn't care about physical attacks, she can just equip Magician's Eye and both Rose Quartzes and do 20000 damage with 2x Soul Beat :ohdear: If you keep the Rose Quartz in, it would be wise to both nerf the shit out of it, and make it an accessory instead of a Temper.
- Asura Helm / Asura Mastergrade Armor: Lategame, but they still make Mu into an unstoppable death machine. Way too good.
Boss steals should be interesting, but it's better for them to be gimmicky stuff that could be viable if you work your build around them. A lot of the boss weapons you can get are like this, so those are good.
3) Risktaker is broken.
Full investment in this Boost costs you about 20% of your HP, DEF, and MDF, but you get around 50% crit and evade. Combined with cloaks and passives (particularly with Rose Edge Argenta) you wind up with like 80%+ crit and evade. This is ridiculous.
4) Claw combos are broken.
But you already knew that. If you want to keep the combo thing, I recommend trimming a few skills from the list and arranging them so combos just consist of two moves. If it were up to me I'd arrange them into starters that have support effects, and finishers that do their ideal damage in different situations. For instance, the defense-lowering and paralyzing skills would be starters and the high-hp/ low-hp moves would be finishers. Stuff like Quadra Blow, which is extremely powerful by itself, shouldn't be able to be used in a combo. Hell Gate Upper could be reworked into a stand-alone move, I guess.
5) Infinite MP and TP.
MP and TP basically never run out thanks to low skill costs and regeneration passives. It's particularly noticeable for Meguka Argenta since she regens more MP each turn than her spells cost. This isn't a big deal for most skills since they're balanced around the idea that you'll be using them every turn, but some high-end stuff like Volcannon Trap really shouldn't be going off every turn. "Ultimate" skills should have their costs raised dramatically.
Those are the five major issues I think need addressing to "fix" the game. Everything listed below is just nitpicks.
- As a general piece of advice, be careful when handing out bonuses to stats like evade and crit. Remember, 10% evade is exactly as effective at the end of the game as it is at the start. That stuff adds up.
- Sword skills are kind of underwhelming, I think they're conceptually flawed. Fire Sealing Pillar silence rarely procs. Deadly Frost being powered by LUK is strange, since ways to stack LUK are very rare. Shadowforce is a poor final skill since Mu being low on MP basically doesn't happen. Fuukenshou is the only real reason to use swords, since AoE skills are uncommon in this game. Also, is there any particular reason swords boost MAT, aside from Haja Slash? I don't really understand what role swords are supposed to fill.
- Why does the final spear skill require most of the claw tree? D:
- It'd be nice if gun skills didn't require most of the bow skills, too.
- Killing Aura is pretty OP and should probably be nerfed. (On the other hand, it's totally rad.
Mu throws away her remorse...)
- Doublesmash is wicked OP and should probably be removed.
- By default in RMVX, counterattacks prevent enemy physical attacks from hitting you, making it effectively stack with evade. You might want to look into getting the script that makes enemy hits still go through when a counter procs, because otherwise Sixth Sense is pretty broke.
- The Lucky Coin
doubling your Sil gain is pretty extreme, and it seems like equipment prices are set with it in mind. (It does increase your target rate though, which makes it interesting, so I'm not complaining too much about being stuck using it)
Next, the bugs I managed to spot:
- Vulcan Storm doesn't seem to work (bows really need this to compete with guns, too)
- Hundred Pierce doesn't seem to work
- Shroud Edge doesn't seem to work correctly
- In the top right corner of the Set Tower, there's a chest that says it gives you a "Silver Spear", but it doesn't get added to your inventory
- The Neon Fang's description text runs off the screen
- You can use True Thorn Slice outside of battle (which does nothing but waste your HP :V )
- Sonya will tell you the Cestuswood is the west, but it's to the east.
- If you go into the basement of Ryuko Cave again after beating the boss, the scene and boss fight will occur again. (I realize this might be intentional for grinding the boss for testing, but I want those treasure chests down there!)
- The locksmith will give you another key each time you talk to her (which is pointless, but there it is)
And finally, some general suggestions.
- If possible, it would be good if running and skipping dialog didn't use the same key.
- The intro dialog could use some work. The exposition is bit awkward and Argenta's reactions are pretty weak.
- The prison could use a lot more polish, seeing as you can't talk to or free any of the prisoners.
- No comment on Nacht dropping Argenta's mom's knife?
- The third password in the factory is basically impossible to know. And unlike the second one, googling taxi cab numbers will just get you phone numbers. FYI it would be better to have the passwords be some kind of puzzle that can be solved entirely within the game (forcing them to actually do the math to get the constant would be a fine idea, for instance

)
- I like that examining every little thing gets you a quip from Argenta, but it seems to drop off after a few towns. Please continue doing this, it's very entertaining!