[HoneyBadger]

I think Dai Onis are *meant* to be the best recruitable SCs in the game, but they fail on several counts.

In addition to the bad armour, they've got low research ability, and they're capital only-which is an issue for them, unlike Niefelheim, who can mass-produce regular Niefel Jotuns. A high bless with Yomi isn't worth considering, because you have no sacred recruits, and no really good sacred National summons. It's an expensive trial to SC them, and while you're doing that, other Nations are beating you in research and with their own sacred troops and SCs.

If Yomi had a sacred recruitable demon, then I think they'd be much more SC worthy, but since they don't, it becomes much less cost effective to give them the bless they need, and they can't forge well enough, early enough, to make up the lack.