Yes, Ice Needles can be set as a battle skill, and used 3 times at 99 Fury (or more with Berserk).
Crono vs Carlie: Carlie against someone with finite resources and no status/OHKO offence tends to win.
Crono vs Kornell: Crono is durable enough not to be 2HKOed, and is much, much faster, so he should win this slugfest.
Crono vs Beowulf: Yeah, Crono's offence is too bad, here, and his MDef doesn't help so Drain will usually hit, and then Shock to kill.
Crono vs Fuse: Crono has a 3-2 here, so he can... kinda try to heal-lock? Spincut heal-locks before the doubleturns, but he'll need to spend considerably more resources otherwise. Fuse can pretty much just heal unless he's not pressured, at which point he attacks and any damage he does sticks.
Crono vs Dekar: Crono is just shy of always doubling, so does so after the first turn in effect. Dekar has 1.67/1.32 durability so Crono is very obviously going to try for a magic blitz here. Luminaire is a 4HKO. But going for this gives Dekar a healing IP. And I can't see any other way for Crono to win. Any attempts to not put on pressure lead to Dekar just 2HKOing him.
Crono vs Landis: Landis has a 4HKO against the somewhat durable Crono, and status is out. Well then.
Crono vs Adray: Adray absorbs lightning. He has about 78% pdur with this awful-def armour (but it's still SO3 defence, so it's not that bad). Crono 2HKOs this with Rainbow Confuse so I think he probably wants to go for that, since he's still faster. So heal-lock until a double, then kill, and as per previous Adray comments I see even Rainbow Crono doubling before running out of MP. More respect for Adray's speed would tilt this, though, since strictly speaking Adray just needs to wait for one shot of MP damage to dry out Crono. That said Adray's MP damage is kinda bad so I don't see this happening in time either... Crono just needs a 5-4. Though, come to think of it, Adray doesn't want to absorb lightning, as it will keep his defence higher and ward off any 2HKO. At that point I think he's probably safe... just heal in response to anything Crono does, and the MP reserves will win. Crono can only win by trying to chip with something free, but that doesn't heal-lock unless a double is upcoming (and even then, only with the Rainbow, so the doubles don't come often), and Adray can MP-damage in response. Okay, yeah. Adray does win, but lightning resistance isn't why!
Crono vs Chrom: Crono misses the double here, but he's still looking pretty good, I think? He does have a 4-3, and Luminaire is a 3HKO as usual... oh shit Chrom can heal. But... no, Crono pulls it out anyway, Luminaire does 48% to Chrom and Chrom can only heal 35%, so after two Luminaires with the 4-3 coming along, 2 more Luminaires will kill. There are a lot of ways for Chrom to win this, though; he's better off trying to attack and hoping for an Aether proc (although the healing won't be enough, it could let him two-round?), or he can dodge (53% chance that happens at least once), but I'm not really inclined to respect any of this. Maybe I feel like throwing Crono a bone in a field where he faced a ridiculous number of healers, I dunno.
Crono is so awful against healers. 3HKOing with a 3-2 is decent for heal-locks (not that he always 3-2's) in theory, but he doesn't have the resources to make it work. He'd kill for some sort of status.
Samurai (FFT) vs Carlie: Samurai can stall with Murasame healing for a... long time against Carlie, who is below average damage while Murasame heals 38%. Carlie will of course Black Curse right away but Samurai doesn't give a shit, as SD3 stat downs don't affect healing I'm pretty sure, so only the defensive hit matters. Samurai is slower so will be muscled down, but with Kiyomori... nah, it's not worth it. Yeah, think Carlie has this, even if Black Curse's effect on her own damage is pretty modest (I don't recall).
Samurai vs Kornell: Oh gee, Samurai is faster? Ew. Kiyomori, start attacking? Don't think the healing is good enough here, Kornell hits a bit too hard. Think Samurai 4HKOs here, though, and isn't reducing Kornell that low... so yeah.
Samurai vs Beowulf: Uh yeah, some status or other.
Samurai vs Fuse: Slow just makes Fuse turtle until it wears off (which is quickly), FFT confuse not very scary (especially since Fuse will randomly Mindheal it away!), so only death sentence can win this fight. 10% status... yeah not happening here, since Samurai has to block two status effects so the HP/healing isn't that good.
Samurai vs Dekar: Seems pretty straightforward thanks to that two-hit sword, Samurai not that much faster and can't put a big dent in Dekar's HP, long fights just let Dekar build up IP over time and do nasty things like attack buffing. There is turn 5 status but slow or confuse don't win the fight for Samurai, really, so it's 10% + give Dekar two extra turns. Not feeling like hyping any of that.
Samurai vs Landis: Block freeze, and whatever from there.
Samurai vs Adray: Don't think samurai blocks freeze, so ICE NEEDLES wins this sigh. Samurai only 3HKOs, so his/her only shot is to status Adray while he heals up. Muramasa does put on a lot of pressure, which helps, but Adray can block ID so it's not a big bother for him... confuse bleh, as usual doesn't mean much. Slow then blitz is the best hope, but slow doesn't put that much pressure on. Probably Adray.
Samurai vs Chrom: Okay, unlike Dekar/Fuse/etc., Chrom has no real way to put this away short of Aethering some ridiculous number of times in a row, and his healing is far less good so Death Sentence probably does kick in.
Most of his/her matches give me headaches so I could be argued on some of these. I stopped trying to be terribly analytical past the first two really. Bunch of weird pressure/counterpressure fights.
Crono 3-5
Samurai 2-6