New Year Corrin (M)

High defense close counter build that can deal with other bow units quite well.

Acts as a decent defensive support, giving adjacent allies +5 def/res in combat via Hama Ya and Spur Def/Res.

I also run him in a team with S!Sharena, who has Res and Def Tactic on her, boosting Corrin's defensive capabilities even further.

This build makes Corrin becoming more of a offensive archer.
Just like what the build that is shown above, corrin needs to reach HP below 50% in order to be really powerful.
He can quad and one-round lot of enemies thanks to brashperation + brazen atk/def build. For the special options, it's recommended special that have 3 charge cooldown like bonfire or luna, in order for corrin proc the special when he's quading. 2 charge cooldown is also not a bad option, but it's not really good vs tanky units.
Desperation 3 is not needed in case you don't have Shanna or don't wanna waste it on Corrin, due to brash assault only work when below 50% HP anyway.
Downside of this build is that, it requires Corrin to take hits to reach 50% health, so it's better for Corrin to fight physical unit due to low res and have a support units to help his survability and buff his attack with bunch of drive and spur atk.

A budget friendly build that excel at support, it makes use of all his default skill.

His default kit weapon bow 'Hama ya', support skill 'Rally Def/Res' & C skill ' Spur Def/Res 2’ & Seal 'Drive Def 2' will boost defensive of Ally by total of 11 def/9 res. If an ally get doubled by follow-up attack, they can survive with damage reduction of 22 Def/18 Res bulk while increased damage from special skills such as Bonfire, Ignis, Glacies & Iceberg. This work well with distance-counter unit who excel tanking at enemy-phase and counter kill with their special skill while equip with B skill ‘quick riposte 3’ or ‘Vengeful Fighter 3’

The B Skill 'Bowbreaker 3' on New Year Corrin (M) allow him to hard counter bow unit that rally heavily on speed, especially Brave Lyn due to her B skill 'Sacae's Blessing' which render distance-counter unit unable to counter (barring Dragonstone users) and then his specials skill ‘bonfire’ should be charge in the next round for the next target.

I obviously haven't completely built him nonetheless, this is still a build that is quite useful for NY!Corrin. This mostly focuses on him being an offensive unit who can get rid of distant range units. With his already high defense, I didn't focus too much on that.

Weapon | I've equipped just a Brave Bow because I don't really think Corrin is worth wasting my time upgrading my 4 star Gordin. But if you want to increase his ability to OHKO enemies, Brave Bow+ does have more attack.

Assist | I use reposition for two things. The first, to keep less bulky units (like Nino for example) out of harm's way. The second is to give dancers a leg up. Since they can't dance each other, if they need an extra turn to reach a far-off enemy, I use reposition to boost them two spaces so they can then attack the enemy. You're probably going to do this for Azura mostly since Ninian and Olivia don't have the offensive power Azura has. You can also do this for other units as well, especially if you don't have a dancer on your team or any other reason.

Special | Since his defense is his best stat, it only makes sense to have a special that capitalizes on it. I'm using Bonfire because I love Henry, don't have a Boey, and need Robin (F) for another skill inheritance. However, if you're not like me and don't love Henry to death, you can use him or any of the heroes listed here (https://fireemblem.gamepress.gg/special-skills/ignis) to get Ignis which increases his damage output by 80% of defense stat rather than Bonfire's 50%. It does happen to have a slower charge time but using it with his ability to double (and quad) should allow you to activate it quickly. At the same time, his ability to double/quad does mean you can spam Bonfire more easily. It's honestly up to you to decide which is better for NY!Corrin.

Slot A | Fury can do two things for NY!Corrin: it can boost his Atk/Spd/Def/Res, and it can safely lower his HP (it won't kill him by itself in other words) which is rather useful for this build and the primary reason I've given it to him. Alternatively, if you really really love Corrin you can always give him Steady Breath. Although it isn't necessarily recommended you do so it can certainly boost your ability to spam specials. That's if you're looking to play a slightly more defensive role, however. For the most part, this build is intended for a more offensive play of Corrin.

Slot B & Seal | Desperation + Brash Assault is probably a fairly familiar combination. It basically allows you to double enemies you initiate combat with that attack from range 2. Combine that with a ridiculously high speed or a Brave weapon (which allows you to double any enemy you initiate combat with) so long as your HP is low enough you can quad any enemy in your vicinity. Who cares about speed, am I right? Plus, even if he's a unit that can be easily doubled thanks to having only 25 Spd with the Brave Bow, he still has a high defense. Just be wary around mages. High Spd/Atk mages like Nino will more than likely OHKO him if you don't take care of her first.

Slot C | This is pretty explainable - this seal lowers the Def of any enemy two spaces away. A Threaten Def 3 is fairly easy to come by as you only need a 4 star Michalis or Peri.

The total SP cost with all the skills/weapons/etc. upgraded fully: 1575 SP. It's quite expensive and completing his build is something I recommend to those that have built most of their other units. That being said, he honestly doesn't need a complete build to work. The weapons and skills equipped to my Corrin aren't all 3, but they still work.

This is a supportive build that allows Corrin to smoke out 3 stats at once and cripple the enemy team. The B skill and seal is actually flexible as you can use skills like windsweep to safely poke down armored teams or using vantage and QR seal to immediately put the debuffs to use. The debuff smoke should cripple powerful units in the arena and allow the rest of your team an easy time cleaning up an enemy that got essentially demoted to 4 star level stats. The build is expensive but it's a lot of fun to use in both PVE and PVP.