How's TA on Nino? (Bonus: Corrin(M) Worth Investing?)

Nino can kill red units so TA on her is actually worse than an empty A-slot. She excels with Swift sparrow/L&D/Fury.

Male corrin is pretty bad even with optimal IV's. He's not worth 20k feathers IMO.

Nino's usual A skill of Fury is much better. TA is best for units with good bulk and middling offenses, and that is absolutely not Nino.

M!Corrin with optimal IVs I'd definitely say is worth the investment. Giving him Life and Death or Swift Sparrow turns him into a monster on initiation, thanks to his innate Darting Blow 2 with Yato. He has good bulk and great offenses given investment.

Enough opinions have been given about Nino and mine wouldn't add anything new, so I'll add a few words about Corrin.

He's one of my top sword units, because I invested in him quite heavily. I was debating whether it would be better to give him fury/lnd/swift sparrow. Fury makes him a tank with good def (31) and decent res (27) combined with high speed (38) and alright attack (51). This speed stat makes it so that he has enough speed to not get doubled by other swords, which is valuable and on initiation Corrin can get to 42 spd, which should let you double the targets that require two strikes to die. LnD would hinder his defenses which wouldn't be too worth it in his case and Swift Sparrow makes him focused solely on player phase where it gives him +4 atk +8 spd, but with only 35 he might get doubled while defending by some faster swords (espcially in higher tiers where 40+ spd Ryoma is not a rare sight).

For those reasons I went with fury + desperation and draconic aura, but I don't know if I can recommend him to you, because it depends on how much you like him and also whether you already have a desperation sworduser.

I personally use him much more often than Ryoma or Ike, because he can easily tank and then start killing, which lets you create a much more diverse team than just slapping a distant counter swordsman in there.

Corrin(M) falls into the long list of middling red sword users that have no real value unless your'e willing to spend a ton on them to catch them up to their betters (especially since he comes with no skills of value) or you're looking for fillers for Arena Assault. Corrin's problem is he excels at nothing. +Spd is as fast as neutral Ryoma for example. He's not as bulky as Ike. Etc.

If it were me, I'd ignore the optimal builds and concentrate on making him at least good at something. If you Fury him, he's still not going to be fast enough to keep up with typical Lucina and Ryoma builds, and half the Ikes out there run Swordbreaker. So you could also consider using Swordbreaker for a B skill. You could also L&D 2 him (I wouldn't go with 3).

I got a 5 star one a month ago and it's still sitting at level 1 unused. I've considered sending him home a couple times. So don't spend too much on him, because you're unlikely to use him once you get better units.

Hmm... I don't consider a unit a Reinhardt counter unless they can survive his QP/Moonbow variant. That's not something -RES Nino can do without Triangle Adept or a similar investment. She is a great all purpose nuke and Triangle Adept does nothing to help her face off against Green mages (granted at -RES you probably won't want to and they usually run Green Tomebreaker just to kill Nino) so it's really up to the needs of your team comp.

I haven't invested in my Nino since the early days of inheritance but she's still a dominant force among my units running the poorly optimized combo of Deathblow and Vantage. No matter what A slot you end up picking you'll probably see her excel in that role.

TA is absolutely not a good choice for Nino, because she can usually kill a lot of red sword units no problem, and sometimes even red mages. Life and Death has been my favorite A slot for Nino, which is a +speed -res too. With Life and Death 3 and -res Nino can still tank Reinhardt, but only to an extent. I've found that Death Blow Reinhardt will kill Nino before she can do anything. You should keep Desperation on Nino and put Ardent Sacrifice on her, since one use of Ardent Sacrifice puts her in Desperation 3 range allowing her to possibly kill alot of distant counter units like Ike or Ryoma before they can hit back. I wouldn't use Corrin(M), as there are many other sword units that can perform much better than him and are much more common, like Hana, who already has Life and Death so you don't need to inherit it into her, although get rid of the Armorslayer. If you have a Marth or Lyn you should use them instead, as they do so much better than Corrin(M). You could also run Olivia (the normal one) instead to buff the team and dance to let Nino and your other teammates do more, but I personally like to use a high damage dealing sword user than Olivia.