Copied and pasted from here, in attempt to solve a mystery about Fates' gameplay mechanics:
https://www.reddit.com/r/fireemblem/comments/53yqqc/lets_attempt_to_derive_the_avatars_attack_stance/
Resources are out there for his growth rates, his mods, even his personal pair-up bonuses.
But as far as I know, no such compilation is out there for the attack stance support bonuses in Hit, Avoid, Critical, and Evade. And I know that Serenes' postings cannot be the complete story here, as my Avatar gives different bonuses than they do. (On that note, Serenes also only shows the pattern of personal pair-up bonuses for Luck flaws at the currently time). Let's try to crack this mystery. What bonuses does your Avatar give to someone when they are standing next to to them, at what support ranks, and what is your boon/bane/talent. I have a +MAG/-LCK Dark Mage Male Avatar. He gives +15 Hit, +5 Avoid, and +9 Crit when standing next to his wife (S-rank). This contrasts with what Serenes thinks the answer is, which claims +15 Hit, +5 Avoid, +6 Crit, +5 Evade. If we build up a sufficiently large sample size of our boons/banes/talents and our attack stance bonuses, we can solve this mystery and figure out how it works. So post away so we can gather the data and figure out how it works.