Okay, some revised calculations with superior Dhyer numbers:
-Cure Plus followed by buffing is her opening double. Xorn will then get in three attacks thanks to the recharge more than offsetting the speed boost, but they won't kill, and from there Shania is free to heal, restore SP, restore MP, rebuff as needed without using doubles, building up stock, and chipping Xorn down to just above 75%.
-With the exact effects of Sanlittobell's defence, I now know that Shania can tank one Dark Hymn while buffed then two more after being debuffed. Assuming she is only tripled after her first big double, then, she can survive anything Xorn does thereafter. She doesn't need to use Shining Zephyr on a double, thus (which she really doesn't want to due to recharge, yeah).
-In Dhyer's stat topic, the kill point is somewhat lower, due to recharge times being considered. This gives Shania a lot more room to maneuver, and in fact she doesn't need to go for huge damage. She can do 489 considering Xorn's defences with an unbuffed double, and only needs to do ~1000 total, which allows, for, say, buffed L1 spell + physical to be good enough. At this figure, even if Xorn got a turn -immediately- after Shania's and uses dispel immediately, he'd only get two more turns thereafter. In practice, she may well have even more leeway, so she can use a stronger spell, for those who use slightly higher kill points. Too lazy to math out exactly what the max is.
-It's very possible Xorn knockback can tilt this, but I'm not sure how much credit I want to give him for that, as mentioned. I probably just throw it out in exchange for not holding any potential PC knockback against him (granted, PC knockback does require some skill setup, so I could see saying otherwise). Without knockback, I'm increasingly sure Shania should take this.
Now, for Khalamari... I'm now certain I was Level 11 for Khalamari. Average HP is 72.5, average Agility is 19 (making Khala slightly slow). Flame Breath does 35 (30 to 40), meaning that Guv (70 HP) is borderline 2HKOed on average. (At Level 10 he is always 2HKOed, at Level 12 almost never.) His physical does 31 damage less a quarter of the target's defence, too lazy to work out what that is so yeah let's go with 20.
He halves fire, resists ice and wind by 25%, is vulnerable to poison, halves blind and Sap, and immunes other status effects, for future reference.
I may try to figure out exact PC damage/defence at some point for more precise numbers, but not now. EDIT: I lied, here you all go.
For Guv, his best damage at this point is with a spear. If he has invested all his SP into spears, he will have Attack+10. With a far more modest investment, +5. If he's ignoring spears entirely... well they're still his best damage, or tied with Boomerang and +5. I'm going to assume a modest spear investment as a compromise.
Spear attack with Attack+5 = 24 damage
For Yangus, if he has invested all his SP in scythes, his best damage is 34 with Wind Sickles. A modest investment in scythes leaves his best damage as 31 damage physical. No investment in scythes drops that slightly, but it still beats anything else. Again, going with the modest version:
Scythe attack with Attack+5 = 31 damage
Average damage for Khalamari is thus 27.5. This makes is against his defence, but DQ defence kinda sucks so it shouldn't matter much if you used randoms instead. This makes him about 1.5PCHP to me, apply your own scaling as you will.
Finally, his non-firebreath attacks:
Guv defence: 12+17+3+7 = 39
Yangus defence: 13+12+3+7 = 35
Thus, Khalamari's physicals do 22 (a solid 4HKO). Apparently he also has a MT tentacle swipe which does somewhat less (75% multiplier?) but I'm not sure how often this will matter, maybe against a FE mage when he needs to avoid counters and still wants to hit physical defence.