Mana Storm becomes largely obsolete if you put Nell in Siren, as Siren’s basic spell does the same thing as Mana Storm for 1 skill bar.
Normal Nell builds up boost bar but who are you going to put that boost bar to use with if your team is some boost oriented team? You need a character to make that boost worthwhile. The problem with normal Nell is she has crap for damage.
Plus, boost mode only really matters in boss fights 'cuz most normal fights end in like 2 turns (Mana Storm/Siren spell, miscellaneous hit)
Luplus isn’t all that great a summon. You can probably kill most fights in the game before it makes significant difference, except for maybe the Shadow Stalker fight… but you wouldn’t have the Luplus summon for that one anyhow. There are plenty of better ways to put your skill bars to use, and none of those force you to wait a year before Iris gets to go again.
Jiptus Edge and Diemia Nell are pretty solid, really. Better than Thanatos and Faustus for their respective characters, at the very least. You really can only take one or the other for a team, though, since they really shine when you have someone like Plua/Normal Edge building bar for your team. Diemia does require some setup time, though (Mind’s Eye and all that).
As for “too slow,” Iris has several knockback attacks, your other character should have knockback attacks, you can add Quick/Delay to your gear…
Meanwhile, Plua just kinda does crap for damage until boost mode, then he does okay damage. A team of Iris, Plua Edge, normal Nell has quite possibly the worst boost mode damage output in the game, even if they’re in boost every rotation through the team order.
I don’t think Plua is very good at all (base damage output is atrocious till boost mode without elemental weakness). Plua Edge + Siren Nell is retarded good, but that’s more a function of Siren having really good skills, since Normal Edge/Siren Nell works really well if you occasionally have Iris tag in for battery purposes.
Same with normal Nell. Normal Nell sucks (bad damage output, armor isn’t super awesome either), but normal Nell + Jiptus Edge is pretty decent.
I personally think, as standalone outfits, Iris, normal Edge, and Siren Nell are good, and the rest are varying degrees of suck. But that’s like saying Wolverine is good 1on1 in MvC2.
Seriously though, Jiptus and Diemia ain’t that bad. I’m having trouble seeing how Thanatos is better than Jiptus except for like… fighting Shadow Stalker as soon as the fight is available.
The problem with tiering Atelier Iris 3 (or Atelier Iris games in general) is that they’re way too easy. So even if a character sucks, you can get by and even make them look pretty good just because of the game’s battle system. Like Thanatos Edge is utter crap but you can easily breeze through most fights with Thanatos Edge.