Shadow Hearts 3 -
So I settled on a challenge. I will use only two PCs (challenge starts once I got party choice, i.e. Alcatraz). There may be another light rule or two (Mind's Eye ban almost for sure), but that's basically it. My plan is to use Johnny and Shania although Johnny's SP might drive me mad in boss fights, we'll see. Most of the early dungeons force a PC anyway, so I will be using forced PC + Shania for those.
Anyway, the challenge begins in Alcatraz, as mentioned, using Shania + Mao. I initially keep Mao with her starting Capricorn stellar chart, but quickly switch out to the much smaller Cancer just to get Bright Rage, an M-radius spell which is the most important thing to have at this point. Once I meet Just Us Guys in the prison (oh, the tragedy; 20's America just wasn't ready for their brand of love), I mess with the Capricorn chart so it has one node for each element and start using that instead (it has a lot more nodes).
Anyway, Alcatraz has three randoms. All of them use both a physical attack and a magic attack of their element (which is generally the norm for randoms in this game). Chon Chons are frail and not terribly damaging, but appear in large numbers. Bright Rage off Mao's magic OHKOs them despite the fact that it hits an element strength, so of course anything Shania has also does the trick. Their own turns aren't too scary but they do add up. Byarkis fly, and require two hits to bring down, and their physicals add paralysis. The rate seems low but I still equip accessories to block it because it landing at a bad time could lead to a wipe. Womps are the star of the dungeon; they sometimes with enough stock to often double or combo immediately (and certainly get enough after being hit once or taking one action), and their magic is Red Nova which both blows up stock and hits weakness on Mao, falling just short of a 2HKO. Their physical sets Random Ring which can be frustrating; on their double (which I see often), they use both attacks. The other enemies prefer using their stock for combos. Ambushes are of course the most threatening and while they never lead to an immediate wipe (at least with paralysis immunity) they can certainly be a bit scary and I have to stay awake during them.
During this dungeon, Shania accrues enough Soul Energy to reach Level 3 Ta'tanka which unlocks Arc Rage and Arc Surge, along with Ebony Cluster, a L2 dark spell which hits aerial targets only. The Arc buffs are not ungodly overpowered with only two PCs, but they're useful for the upcoming boss fight. I also get lots of snaps of Womps (photograph + run, the best strategy) since they're needed for one of Shania's statues.
Ronwei
Ronwei is the first boss of the challenge, and is a large step up from the first full-party boss, Igornak, even on a normal playthrough, although certainly nothing compared to most of the later bosses in the game. He specialises in destroying stock and making Mao's life miserable.
He has two main attacks: a physical that destroys stock, and Red Nova, which destroys stock (and 2HKOs Mao). If he gets a double, he will use both Red Nova and another fire spell, Flame Mine, and the combination will off Mao in one round. At low HP, Ronwei picks up multitarget Seal (silence). All of his turns carry a quick hit property except for his somewhat laggy doubles, as is the norm for bosses in this game. Seal has an especially fast recharge time, but otherwise he doesn't go crazy with lapping me like I expect some later bosses to do.
Keeping Ronwei's stock under control is important since those fire spells reliably go after Mao. My own Red Nova (both PCs have it) can do this, as can Hard Hit if I actually have 50% stock gauge to play with (doesn't happen too often, the boss is very good at depleting it). Otherwise it's large a matter of watching HP... Shania is quite tanky but even she can drop. My initial run of offence involves Arc Surge, and then using L1 magic from both PCs, particularly Mao's Hail Dust; these do around 78 and 88 damage. Later in the fight as I run out of MP and Arc Surge wears off, I switch to Aqua Edge physicals from Shania as Mao heals, this ends up synergising well with the party being silenced since I don't need to bother healing it. It'd have been even better if I'd been able to have Mao toss in a casting of Rage, but I missed the stellar for this (have since picked it up).