Okay but, what's the difference between carrying two Dancers and carrying one Dancer and one Buffer especifically for Nino?
You're not wasting the Dancer since this is a AxuraXEirika comparison and not a AxuraXAny other Dancer one.
Besides, Axura can do the job of a buffer and a Dancer, so she takes less resources.
I have Axezura perform various jobs, she's not just there to buff Nino. Hell, most of the time, I don't even need the buffs for the first attack which means I get an attack and a second and even more powerful attack after that.
And even besides that, Nino still doesn't take much investment. All Axezura is is the easiest way to buff Nino really high. When all she really needs is one good buffer, which can be Eirika or whiever else, she makes for a really easy to use unit.
Like, what about promoting an unit is "heavy investment"?
She's still an inferior buffer to the other options like Eirika because the buff is weaker (i.e Nino's blade tome doesn't get powered up as much). Combined with the "tap the unit to use their turn and then dance them" approach that you will inevitably have to rely on, she's doing both the buffing and dancing job less efficiently. Which is why having a dedicated buffer plus a dancer gives you more options.
I mean personally, I don't even like the idea of having a dedicated buffer who buffs one really powerful unit (unless it's TT and Chain Challenge where I have Elise offer heals, Def buffs, and Res buffs. Or Genny too). Would rather spread the buff skills out amongst a bunch of powerful units so that I have more options. But Axezura definitely isn't designed to be a dedicated buffer.
If you're big into buffing a specific unit, then having a dedicated buffer AND Axezura would probably be ideal, since it gives you a lot of flexibility in how your spread out your buffs. But trying to have Axezura do both is going to cause you limitations, especially since she's more frail than other buffers like Eirika. One common strat is to have a bulky buffer bait an enemy in for your Nino or whoever else so that Nino can follow-up on Player Phase. Axezura can't really do this.
A minor nitpick: Brave Lucina can't function as a blade tome buffer in the same way that Eirika/Ephraim/axe Azura can, as her buffs are in-battle (Drive and Spur) - only out-of-battle buffs (Hone, Fortify, and Rally) count for the effect of blade tomes. Her buffs (except Drive Speed) only apply to physical units anyway, so she's of no help at all to a blade mage. Unless you do something like Rally Spd/Res as her assist, Hone Attack as her C skill, and Fortify Def as her seal. But literally anyone can do that (except healers), so you're just wasting her default Drive Speed, which is pretty good.
40,000 feathers is not that much these days, anyway. Depending on how well you do in the arena, Tempest Trials, and Voting Gauntlets, you can get that in three or four weeks. Not that heavy an investment any more. And both Nino and Eirika only need skills that are available from common 3-4 star units that many players will have several of, so that 40,000 feathers is all you need for them. I'll admit Eirika isn't the most common character, but if you pull reds often enough you have a good chance of finding her sooner or later. Alternatively, you could get axe Azura from the current banner, or if you're particularly lucky, Ephraim is good too.
I think Inigo really needs the extra 4 Mt from Gronnraven+, personally. His Atk will be painfully low without it (and I have one who is -Atk, so he really needs it). Triangle Adept helps, but it's not enough: that missing 4 Mt will leave him unable to kill brave Lyn or Reinhardt if they have Fortify Cavalry active, but he would kill both with Gronnraven+, even if you throw in a few merges on Lyn/Reinhardt. I think the only instance where you can afford to drop that 4 Mt is in the case of cavalry or flying blade tomes, because of how you're stacking such big buffs on them; for raven tomes, I think the extra 4 Mt is always needed. So that's at least 20,000 feathers spent just to inherit a unit away; it's a different sort of investment to spending on a unit you'll actually use, but the fact you lose the unit if you inherit them away makes it a heavier investment, I think.
Investment is always going to be subjective to interpretation to some degree, especially when it comes to the units used. I have a Gronnraven+, Rein/Blyn destroying Inigo myself, but I basically had everything I needed for him anyway when I pulled him, and I had no plans to really use the units I used for SI. So to me, personally, that wasn't a big deal.
Feathers are an objectively quantifiable resource though (i.e they're a literal number), and they are limited. While it is easier to earn them these days, you still only get big packs of them on IS's terms and schedule. And how much you get depends on how powerful your units really are. And if you REALLY want to get lots of them, you need to invest your Stamina Potions for things like Tempest Trials.
And like you just said, you're probably gonna get 20,000 over the course of about a month, and that's assuming you're extremely dedicated to the game...so that's a huge time investment too.
So yeah, the amount of feathers are an investment, one of the bigger ones in general IMO.
I don't think Nino is the highest investment unit out there, not by a longshot, and Inigo is definitely more overall investment with the amount of units you need for inheritance. But Nino still requires feathers at a baseline unlike a lot of powerful characters, and requires getting other units that can buff her and building those appropriately. That's still an investment, just a different kind. Maybe "heavy" was too strong a word, maybe I should say "moderate". But I don't think she's low investment. That'd be comparing her to someone like Delthea.
As for Inigo, most people actually don't bother with Gronnraven+ because like I said, it's not needed. IIRC, the only drawback of vanilla Gronnraven is that a highly merged Brave Lyn with cavalry buffs might take two rounds of combat, which Inigo won't be able to deal with unless he heals. Which you can still work with. Gronnraven+ makes it much less likely you need to heal, which is better, but he can still check Brave Lyn and Reinhardt in most situations with just vanilla. The introduction of SS Forge has made vanilla Gronnraven even more viable too.
