Because movement abilities always need more hype.
Farmel, as those who've played Wild ARMs 4 will remember, is a gimmick boss designed to be fought by a WA4 team, not in a duel. (Same deal with a lot of Brionac, really. Belial & Lambda's translation to the DL is extremely weird.). She's got three moves: Darkness Stance, Fortress Stance, and Barrier Stance. She's got a Hamedo-like 9999 damage counter to anything you try and do to her while she's in Darkness Stance, and the only way to break it is to force her to move out of the center hex. In-game, this means Arnaud's Isolate, and allegedly Yulie's Replace as well. This move alone means that people in the vast majority of combat systems are instantly out of luck in this fight, unless you count how much movement is going on in FMVs or something. Even if you can get beyond that, she's got her other two stances, which null all physicals and null all magic respectively.
For interpretation purposes, let's not let Farmel spam Darkness Stance after it's been broken once (like in game), but we will let her spam whichever of the other two stances she likes (she won't do this in-game). So you need to hit the full trifecta to win. On the bright side, you don't need to win fast; she never attacks.
One tricky interpretation issue is movement spells that also do damage - I don't believe any such ability exists in WA4, so it's hard to say. You can see it as breaking Darkness Stance, eating Finest Arts and doing nothing, or working as far as breaking the stance but still generating a 2x PCHP counter. Myself, I'd say that so long as the movement ability is cataclysmic enough, it'll work. It's tougher for "damage abilities that also move-" certainly your average SH2-3/Grandia physical shouldn't work. On the other hand, hitting someone into the air with a Grandia III critical or the SH "air" moves is mostly used for positioning. Still, I'd have to say that those don't work, at least in my view. There should be a clear "rearrange the field" or "move a character off this area guaranteed" thing attached to an ability, like Grandia II's Gravity, or Grandia II Howlnado (at least IIRC Howlnado correctly).
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Some ideas so far:
Arnaud clearly has this in the bag, as in game. Isolate / Physical / Blast. If Yulie Replace hype works, then she wins with Physical/Material. For that matter, the Divine Weapon's got a "splay the party about in random locations" move, too, IIRC.
Fire Emblem 9 has a promising start thanks to Shove, but it does worse than you'd think. Tanith and Naesala have both magical and physical damage - ah, but flying units can't Shove. Tough. Instead, the winner is... Calill?! Well, assuming her Con permits her to Shove Farmel. Calill has 7 build, meaning she can shove up to 9 Build... for point of comparison, Nephenee has 8 build, so I think calling Farmel 9 build is fair. After that, yes, it's Knife use hype time. Arguably Soren and Ilyana qualify too, but uh no to their Con being high enough to successfully Shove here, and I don't think Soren's knife breaks Defense anyway. (My Soren had 0 Strength at lvl. 20/16 or so, at least.)
The Magic Emperor's got this one in the bag - Tornado breaks Darkness Stance quite nicely (as it randomly tosses the party into the air and into new positions), and even if you see it as earning a counter, Ghaleon just Chaos Shields beforehand. He's got physicals and magic for the rest.
As noted above, Millenia's Howlnado disposes of Darkness Stance, and she's got other physicals and magic to back it up. If you see Howlnado as garnering a counter, then open with Spellbinding Eye to (arguably) turn the counters off before Howlnado. Alfina uses Holy Circle, and then runs near Farmel a lot? I mean, she's using the move command, not an attack, so it shouldn't generate a counter... but the actual movement amount and damage is laughable. If you see it as breaking the Darkness Stance, she wins, but the damage is bad here and she'll run out of SP first if the Darkness Stance doesn't come down.
Final Fantasy characters are in for a tough time. Selphie beats herself up, then wins with The End, but I think she's the only one who's got a clear win. Ramza's Dash breaks Hamedo in-game, so arguably he Tackles Farmel out of the Center Hex, then Rune Sword / Ultimas his way to victory. Zidane uses What's That?! to break Darkness Stance, but doesn't have magical backup. Celes has a very weak argument if you see Vanish as a way of evading the counters - Vanish self, Vanish Farmel (evade counter), Ice3 does damage and isn't nulled thanks to Vanish (evade counter), repeat. Exdeath has Reverse Polarity in one of his forms, which switches rows? Maybe that'll work here?
Disgaea characters can pick Farmel up and toss her... but all their special moves count as physicals, right? I think they're done.
The Secret of Mana Sprite has an extremely bad argument in that PC Confusion causes you to walk in opposite directions, so maybe will cause Farmel to wander out of Darkness Stance herself? Yeah, not likely, especially with boss immunities. There'd be a better argument based off of SoM characters being able to push enemies/villagers around.
Margulis's XS1 form can knock Ziggy into the back row if you didn't stick MOMO behind him, so arguably that counts, except I don't think it has magic damage. His XS2 form has the magic damage but loses the movement ability, unless you count Down. So he's out.
Also, there's another (extremely arguable) way around the stances: A sufficiently powerful dispel move. It's hard to say how well this'll work, as it doesn't in WA4... but then again, all status effects to be dispelled in WA4 are hex effects, and this isn't a hex effect. If normal dispels work, then a ton of fighters suddenly beat Farmel (DQ8 bosses, Xorn, Shion, Magus, etc.). If we require an unusually strong one... well, FF3DS Scholar has both physical and magical damage, and his Scan effect can dispel Hein's Barrier Shift, which is a similar "fundamental weakness is set to the following" move. Might be a few others.
So who else beats Farmel?
