Charlotte my beloved. Conquest wife every time. I love my squishy idiots with Wrath who couldn’t hit the broad side of a barn.
My flavor was Path of Radiance Kieren with Gamble and max crit forge, and I had a revelations 'spin the wheel' based drunk playthrough where I ended up marrying Severa who I critmaxxed to hear "LOSER" more often, and had a bloodline of Rinkah, Keaton and Veloria all to have oni chieftain Death-Blow and great club critmaxxing. What a fantastic playthrough that was. Everyone always hates on Fates story for good reason, but id wager with how customizable it is, everyone has their own special stories of fun things they did with it that few others ever did, and man if that doesn't make it a good game.
Thats actually a specific class I have such a huge soft spot for, Oni Chieftan is one of the most fun classes ever and here is a huge autistic rant on it:
So focusing on birthright first: your only base Oni Chieftan is Rinkah, who falls off early. Hayato and Hinata can get it by heart seal, but that requires using those two which is rare enough as it is when Fates gives you way too many magic users and samurai before you get either of them, or then it asks you to use whole ass heart seal on that. So, I feel like people don't see enough from this class and what it has to offer. Oni Chieftan has absolutely bonkers pair up bonuses by default, giving +4 strength and +4 defense, which is enough to turn just about anyone into a physical tank in Birthright. Rinkah gets A+ supports with Orrochi, Oboro and Kagero. Meanwhile, the Horse Spirit is a Guard Naginata for mages. The other two can't pass Oni Savage by friendship or child seal nearly as easily, being male and having it as a secondary class.
Passing Oni Chieftan as a friendship seal to Orrochi makes an absolute monster of a unit that can get an obscene magic state and speed as a sage, and then friendship seal to get defense and res as a chieftain. After the Rinkah pair up bonus she was hitting 35+ in Def, Res and Mag, and enough skill and speed to be an absolute machine. Passing Oni Chieftan to Kagero or Oboro the same way gives savage blow to them, but the bonus is best used just for having a +def +str backpack for a Ninja, which is really damn nice to have, or makes Oboro hit even harder and be invulnerable on the physical side and giving her access to blacksmith as well is actually crazy fun.
Passing Oni Chieftan to a child also goes crazy. If you get savage blow before getting the child unit, you can make an instant critical hit machine right out the door, especially with Subaki to fix the skill problem and hand Caeldori some well-deserved strength growths. Give that to any samurai or crit build too and you are well on your way. But my favorite thing to do is basically the same as Orrochi before, take a mixed attacker with good res, and make them a fun bundle of states. Mitama works especially well for this, mine turned out with 35+ in every stat except skill.
In revelations you can use it with other Nhorian skills, especally Autur, Severa, or high crit classes like the Furries, and a great club to reach a crit rate of over 100%. I don't think I need to say more.
I hardly ever use Rinkah as anything but a backpack after she reaches level 5, but spreading that class around is some of the most fun you can have in this game.