I completed the Chapter 27 battle in one turn because I just wanted get Revelation over with. My method of defeating Anankos here was by pairing Hinoka with Xander and putting them at the top most tile at the start. Hinoka moved all the way until she was one space away from her topmost tile; she then used Rescue to fetch me close to her. I was paired with Mitama for the Strength and Defense boosts. I approached Anankos and landed some good damage onto him, one of which was from Dragon Fang. Once that was done, I had Caeldori paired with Siegbert fly all the way until she was one tile beneath one of the Generals. She then used her Rescue staff to bring Shigure paired with Azura close to her. Shigure then flew Azura toward me. He then switched into Azura so that she could give me an extra attack. Following that, I landed the final blow.
And now the endgame. My final team: myself, Azura, Gunter, Xander, Hinoka, Camilla, Ryoma, Takumi, Oboro, Shiro, Sophie, and Shigure. Shigure was paired with Azura once again so that Azura would have more mobility (he also served as an added healing unit alongside Hinoka). Xander and Hinoka mostly did there job in taking out any extra enemy units, although Xander could go up against Anankos if he needed to. The same thing applied with Takumi and Oboro, only unlike Xander, Takumi actually did attack Anankos a few times. Shiro and Sophie were there solely to deal with extra enemy units; I chose them as my children units since they are among my favorite children units in the game (Shiro is among my top 10 favorite characters as well, and he was a pretty killer unit in this playthrough thanks to some awesome stats all around and some great skills such as Astra, Rend Heaven, and Savage Blow (thanks Camilla); Sophie was pretty awesome this time around thanks to Aptitude from her mother, Mozu, and gaining access to Aegis and Luna). Ryoma was there to serve as an additional attacker to Anankos
What about Gunter? He was only there as pair-up fodder for myself. I completely forgot that his personal skill is a huge asset to Corrin when paired with him/her. Had I not forgot about it in Chapter 27, I easily would've paired him with myself for that battle. Now that I remembered it as I was selecting my units, I knew Gunter would make the perfect Dual Guard fodder for this battle.
Battle time!
Turns out this wasn't as hard of a fight as I expected (though I have to admit grinding all my units up to Level 20 definitely helped here). Ryoma took out the first Berserker, and Oboro took out the first Sorcerer. Xander took care of the Bow Knight, while Shiro took care of the first Wyvern Lord. I chilled around the center at first to wait for the coast to be clear. Into the next turn, Oboro gets damaged a tiny bit by the Adventurer, and a Dark Knight does a small chunk of damage to Shiro. More reinforcements are sent on the left: another Berserker and another Sorcerer. I reach the Berserker and take it out with ease. Oboro takes out the Sorcerer, and Camilla killed the General with a Hammer and took a huge amount of damage in the process. Sophie took out the Dark Knight, and then Shiro took care of the incoming Paladin when Azura arrived to sing her song. Hinoka healed Shiro afterward.
Now it was time to take out the first arm, the one on the left. Ryoma took out half of the HP there and avoided Anakos's attack. I then moved in to land the finishing blow. A Bow Knight and another Wyvern Lord appeared on the right. Xander took care of the Bow Knight yet again, and Shiro took out the Wyvern Lord, this time with a lucky dodge. It took about two turns to transport Ryoma+Camilla, myself+Gunter, and Takumi+Oboro to reach the other side. The good thing was that little reinforcements were sent on the left in this process. Once they reached the right arm, Hinoka healed up Camilla. I then repeated the same process that I did with left arm: Ryoma softened things up (he even activated Astra with the second hit, but some of the attacks missed) at the cost of receiving lots of damage, and then I proceeded to land the finishing blow. With two arms down, only the head remained. Another Sorcerer and General were sent in around this time. I had Oboro tank up the hits from these two. She then took out the Sorcerer, while Hinoka took out the General when it had the right HP.
After that, all my units closed in on the head. Takumi landed 30 damage to it, and he was protected with a Dual Guard when Anankos tried to attack. Ryoma continued to soften things up, and I landed the final blow... and then we had to deal with his final form: Anankos's heart. A Swordmaster, a Sniper, a Falcon Knight, and an Onmyoji were closing in at this point from the top right, so I had to give it my all this turn. Here we go!
Ryoma goes first... and one of his attacks missed. He gets quite the damage once again in the process. I then proceeded to attack, feeling a little nervous after that one miss from Ryoma. Luckily, one of my hits involved the Dragon Fang. Anankos was left with 13 HP at this point. Takumi proceeds to attack. He will do 12 damage, leaving Anankos at one HP short. I forgot that Dragonskin doesn't negate critical hits, but rather just halves them. Guess where this is going. Takumi readied his bow and the critical flash happens. "Oh, that's it," screams Takumi. He lands the killing blow, dealing 18 damage to finish off Anankos. I was flabbergasted. I didn't think he'd land the final blow; I thought I would have to do it after Azura would sing for me, but nope, Takumi got the job done. My favorite character in the game finished off my Fire Emblem Fates playthrough with a bang! What makes it even better was that during the credits, it was revealed that he and Oboro were the heroes for this battle! My all-time favorite and best unit duo were the final heroes in the end! Quite an amazing moment if you ask me.