Wrath_of_Pie

I would recommend using an external hard drive for backup purposes, that is basically what I do with all of my disc images. Guessing that bd02 in the archive name is just a hash or something.

Did you patch over a clean ISO?

I think v1.7 was definitely better (I did enjoy v1.5 and finished the Arena, although the last boss there is incredibly boring), although the ultimate rebalance would probably require more than just changing stats for obvious reasons. Considering the Defender enemies are vulnerable to Provoke, there really isn't much strategy past that, although they are somewhat vulnerable to Mental Break so that helps in defeating them faster. 60% more HP for every enemy is easy mode compared to Punishment, which goes up to 400% more HP (well, 500% in v2.6) and increases stats as well. Of course, increasing HP only does so much when you can just cast Demi, which hits everything except most bosses and Adamantoise for some reason.

You will still need Demi a bunch in the later random encounters, and the final boss is still difficult, so the late-game tedium will still be there. Luckily, most of the random battles are not that hard if you know what you are doing. (Sanctie in particular is going to be a lot less miserable, which is nice.)

Wayback Machine has it here (it is included despite the title).

Unleashed was at least more interesting, even though Regen is broken in FFIX because it is based on time rather than an actual duration which makes Necron really annoying. I think the intent of Lich was to max out Magic Evasion and try to survive that way, Auto-Life is also a thing as well. IIRC Xenosaga I has a save point bug with PCSX2 in that some save points just reset the game so you probably want to save state before using a save point.

Honestly, there are a few changes I would make, probably starting with the Bribe formula. (True story - I found the offset for Mimic gil drops in the NTSC version, then was disappointed to find out that the cap was 65,535 before considering Gillionaire.) The inflated HP in the Omega Ruins is actually manageable even at my low stats because Poison damage still has the same multiplier as the base game, quite a few enemies are vulnerable to Sleep, others can be Provoked, so the only difficult enemies are Master Tonberry, Varuna, and Great Malboro. (Demonolith probably would be but they can be Slowed, and Stoneproof is really the only ailment resistance you need because Pharaoh's Curse is basically countered with a Remedy.) If you were ever to continue, I would stop at capturing one of each enemy for future Bribing purposes and just finish the game if you can. (60% stat increases are actually rather small compared to what Punishment eventually does, so the hope is that the AI/attacks of the enemies were changed somehow to make it interesting.) Your best bet is waiting for a Steam sale which happens quite often (watching the game should work, then you get e-mail notifications when it goes on sale).

Honestly filling the Sphere Grid is probably overkill for the final boss, although I have no clue what modifications he made since NTSC v1.7. I would actually not just AP grind all at once because you will eventually run out of Power/Magic/Speed Spheres and you will need a source for those. I think you can still get Fortune Spheres from the Arena, but you are probably out of luck on the Luck Spheres. There are also some stat spheres in the temples you can't access because of Dark Aeons (until you defeat them, of course), and a few from lightning dodging. I have the Remaster so I am somewhat familiar with the Expert Sphere Grid, and both sphere grids have a lot of empty spaces. You could probably beat the next few bosses as-is, although Overdrive Sin requires some preparation because he is a damage and ailment resistance check.

Maxing out stats is not possible because all the stat sphere drops in the Monster Arena were replaced with Wings to Discovery drops. Honestly, I think it is difficult to beat the Celestial Weapons with a custom weapon due to their inherent damage properties and innately having Break Damage Limit, although if you going towards Magic then a custom weapon probably wins out. (Break Damage Limit, Magic Booster, and Magic +20% are obvious, and the last ability is probably Magic +10%. In my challenge run, the issue is that I would probably have to replace Magic +10% with One MP Cost, but that might make Overdrive Sin possible. Too bad getting 120 Dark Matter is not easy, probably would involve me murdering Chimerageist repeatedly for them, so ~960 fights required given the 1/8 drop rate as it is a rare drop. Probably would just use a save editor at that point.) If you want Overdrive > AP to be as efficient as possible, you really want Triple Overdrive and Triple AP as well, but that requires items and the time taken to get those items. I was suggesting against it because I thought International capped the AP you could get that way, but it seems I was wrong. Don Tonberry has a common steal of Candle of Life x3, which should help you out as well.

A quick search gave me nothing on Steam other than graphics mods. I am guessing that being a PS2 game originally makes it cumbersome to hack along with the lack of support from Square-Enix, although at least a lot of the mechanical stuff is documented.

I just grinded Yuna up to Reflect for Natus, because the enemies give godly amounts of AP on the Highbridge. Elemental resistance setups would work for the first phase, but Break and Flare could care less about those, so I prefer just casting Reflect. Actions have a Rank value, with a lower rank being functionally faster. Most commands are Rank 3, but Flare is Rank 4 so your observations are not that far off. (If you are curious, Quick Hit is Rank 2 in the International version, but it was Rank 1 in the NTSC version.) Yunalesca is brutal, but I just used Sentinel Auron because her counter in the second and third stages gets rid of buffs except for Reflect. The hard part is making sure Absorb does not screw you over when setting up Double HP (as it is based on maximum HP), and since I was not using Overdrives, that meant I had to time the usage of Stamina Tablets correctly. (Luckily, Yunalesca has it as her steal.)

Actually, I think every main game boss has ailment vulnerabilities in the vanilla game, even if it is irrelevant for a few of them. A time limit for ailments would help less against Sanctie because he can cast Esuna, but in general it would be good for game balance for that to be the case. The good news is that each enemy has specific ailment/debuff resistances, so you can actually adjust the base success rate once the items are adjusted to have 100% infliction rate (or less, if desired) rather than infinite for each boss. The highest infliction rate possible without items is 150% with a -touch and a -strike ability on a weapon, so making such a weapon not possible would probably be needed as well.

Was not aware that such a mod existed, that is nice to know. Sanctie actually has Esuna in his skillset, but he only uses it when he has a status ailment and only when he would otherwise cast Curaga. The real issue is Sanctie is annoying enough that I would probably still prefer Sentinel Auron with Evade & Counter doing all the damage because of Tail Sweep removing all your buffs, but that is probably because I prefer to be as risk-averse as possible. I still think the real answer is modifying the skillsets/AI although making status ailments a thing again for bosses would help.

International changed the sigil names around for some reason, so the Venus Sigil/Crest should correspond to Rikku's Godhand in the International version as per this FAQ.

The Poison damage value is specific to each enemy, although I am not sure that decimal values are compatible so the lowest would be 1% per turn. The actual real issue is that Rikku's items have effectively an infinite infliction rate, so casting Slow is relatively useless in comparison to using a Silver Hourglass because the item always works. Honestly, changing some of the HP totals would be necessary because the Keepers definitely have too much HP. IIRC he re-balanced all the Arena/Dark Aeon (less sure about the Dark Aeons, they are not in the NTSC version of the game) stats because he took away Sphere drops from the Monster Arena.