Tales of the Abyss:
Luke fon Fabre: 4/10. Never really got used to using him and his AI is loltalesmeleeAI. Jewel at least gives him a stretch where he might fit into the party though.
Tear Grants: 7.5/10. Healing battery and a good one, Tales charge times be damned. Back up magic is nice but yeah. Always nice to have in the team.
Jade Curtis: 5/10. Eh, he's kinda there. Spells are quite nice for setting up FOFs and tying things up at least. Boring to control though and the speed is blargh.
Guy Cecil: 7.5/10. Kinda unremarkable early on. Then his C.Core starts picking up speed and he learns a few money moves and jesus. Now he ties enemies up in game like crazy and kites the rest. Can self heal, which is pretty cool in a pinch. Raw defense just sucks though.
Anise Tatlin: 3.5/10. Bloody Howling is awesome. Too bad she gets it way too late. Once she does though, that's pretty much all she does. Unremarkable otherwise
Natalia Luzu Kimlasca-Lanvaldear: 8/10 Team MVP. Secondary healer (worse than Tear), but has range, can snipe safely and enough speed to make the sniping possible. Damage could use some work, but hey. I assume that she gets worse as you amp up the difficulty, but on Normal/Hard, she's awesome.
Asch: DNR. He joins for like one dungeon. God help me if I can remember what he does other than suck though.
Fire Emblem Swordmasters, Heroes and Ravens:
Dieck: 7/10. His early showing is worth a lot for me, especially since early FE6 can be quite the bitch. He kinda slumps later on but still servicable at least. Like Bors, you may consider ditching him for another unit later especially once they get better.
Rutger: 8/10. Never lags. Brings the offense with his speed, class bonus and supports. Mono weapon hurts, but at least its FE6 Swords
Oujay: 5/10. Yeah. I think a 5 works here. Takes a while to get going, never gets WHOAMG but he's quite decent when caught up.
Fir: 7.5/10. Starts off a bit weaker than Rutger, eventually gets better than him. Still, Rutger never has lag and I don't think Fir really outperforms Rutger significantly even when she is finally beating him.
Echidna: 6/10. WHOA. Usable Filler in FE6? Blapshemy. Echidna is probably the best person you an have use axes. Her strength is kinda bad yeah, but the skill lets her use lolFE6axes decently and she's solid otherwise.
Karel(6): 6/10. Usable end game filler. He joins with 1 map left, so he's like SOL for supports. But he's still usable at least.
Guy: 7/10. Solid. Weakish start, but you can drop him if he's not gaining strength. And that Matt support can keep him afloat for a while. Standard swordsmaster offense, although not FE6 level insane.
Raven: 8.5/10. 13 base speed at level 5 with 8 strength. And he has 45/55 growths in those two stats to boot. Jesus Christ. AND he has some fast supports with a couple of really awesome units (Pris/Lucius). BUT BUT HE CAN'T USE AXES WITHOUT -1AS LOSS OMG.
Karel(7): 3/10. Uh...he's usable filler. Bases could use some work (ew Strength and ew HP) and getting him costs you a better unit here as well.
Harken: 6/10. Pretty good objectively. Some of his support options are just lol (Hi Isodora), but his bases are servicable. As a bonus, that Brave Sword he brings along > Karel's Wo Dao to boot.
Karla: 0/10. Karla doesn't even exist until New Game+ (effectively Hector mode). Then you have to train up Bartre, who himself isn't that good, which means you have to dedicate a portion of your EXP resource pool to him AND get him up to level 5 promoted. Oh and after that, he has to fight Karla and both of these idiots have to survive (not difficult with Iron Rune/Bow on Bartre but yeah). When you finally do get Karla, you get a unit that is effectively worse than an average unit that you could've otherwise used Bartre's EXP for wit 2 maps left to go. As I put it once in chat, its like Rolf and Shinon in FE9. You use one shitty unit to get another shitty unit. THIS IS CLEARLY THE WAY. EDIT: Screw it. 0 it is.
Joshua: 7/10. Effectively Guy with better start but worse end due to competition and base support affinity. Still plenty solid and worth utilizing.
Gerik: 7/10. I guess. Gerik's kinda beastly. His con basically means he rarely suffers an AS loss and his bases are pretty notable. Could use more speed growth, but he's fairly strong regardless.
Marisa: 3/10. Way too much effort, but at least she becomes solid if you do the effort in and isn't a total pain in the ass to raise.
Mia(9): 5/10. Can't objectively give FE9 Mia higher than his. Knight Ward laughs at SM speed. Then they have lolMgt due to FE9 Swords and they're less overall durable. Not mounted, so there's no Cantoing. Less move than mounted. But Mia can at least work some supports to get her strength up and her offense is at least workable.
Zihark(9): 5/10. A different variant than Mia trading in some strength from supports for more avoid. Depends on what you value more. Adept vs. Vantage would be a debate here, but Vantage being always active trumps the proc. rate for Adept in FE9 for me.
Stefan(9): 6/10. His stats are lolwat for midgame. I would give him higher except his LUCK (haha wow, luck actually being relevant) makes him get randomly crit blick'd and die and argh why :|
Lucia(9): 1/10. BUT SHE CAN SUPPORT WITH BASTIAN. YESZ
Naesala(9): 5/10. Same comments as Giffca9 anyway. Naesala deals less damage, but flight + doubling the shit out of everything is cool.
Edward: 3/10. Edward is such garbage. The only way he even becomes remotely decent is if he gets massively defense blessed (and I do mean massively). His offense isn't even that good to start and it takes him a while to catch up to Zihark. Caladbolg's +8 Luck is pretty crappy since Edward doesn't have noticable evade. Then on top of that, Wrath gets him gj'd and self owned because hey lack of noticable evade. Oh and when he's finally beating Zihark, its way too late and matters too little. So what the hell is getting Edward points? Well as bad as he is, his offense is pretty valuable for the first few Part 1 maps. Also, before Nolan and Zihark start supporting each other, its possible for Edward to have some leech time with Nolan since they build a support quickly. That's around it. Otherwise, he's another frail but project unit in the DB and god knows how many of those there are >_>.
Zihark(10): 7.5/10. Uh yeah. Much better. Zihark's raw durability sucks, but his offense starts off noticably better. Earth affin, which means that he can support Nolan/Aran/Volug/Jill for some dodge hax shinengans to offset raw durability. However, Micaiah has no authority stars, so he's never really Super Dodger Tank Master. Innate Adept is also pretty cool her.
Vika: 3.5/10. She exists like Muarim for a few maps and flies. Similar score here works.
Nealuchi: 3.5/10. Workable. 36 Speed is quite adequate for a long time. Nealuchi really lacks screen time though and that really hurts since his strike never catches up and he's basically offensively inept after Part 2. He does however, at least fly and have good size for performing rescues and drops. And he can provide some support in a pinch.
Lucia(10): 3/10. roflstomps a map. But said map also has Mordecai and Lethe who are both also roflstomping (so a bit lesser credit here). She is otherwise...pretty bad. But hey, Earth affinity. So at least some incentive exists for her to be used. The offense just sucks by the time she rejoins and she has nothing else to offer other than Earth affin.
Mia(10): 8.5/10. Mia10 is quite awesome and I just might be a bit biased~. Great offensive, and effective dodge also means she's very unlikely to get killed. Adept might as well go on her, which shoots up the offensive worth value and she moves farther than Gatrie. 3rd best GM to me (counting only the core GMs, so no Haar/Brom/Nephenee, etc)
Naesala(10): 8/10. Worst of the royals, but he's still destroying shit. Crossbows keep him in check and from completely one manning the field.
Stefan(10): 6/10. Usable filler like Volke in the endgame if you absolutely need some filler units. And pretty good at that since Trueblades are a good endgame class.