By Phoenix.Capuchin 2017-11-06 17:30:24
Seems your questions were already answered pretty well, but adding my agreement to the NIN discussion - Mythic is far and away the worst of the 4 RMEA katanas to start with.
Heishi is a great DD choice, generally BiS. Along with Blade: Shun, the TP Bonus really helps Blade: Ten shine. Less frequent, but either of Kikoku or Kannagi can also sometimes be top DPS depending on situation, and both are still very solid weapons in any case.
Kikoku provides a lot of bang for your buck (as Arisan mentioned) if you're looking at a NIN RMEA and Aeonic isn't in your near future. It holds up quite well for DPS purposes, often beating Kannagi and occasionally beating Aeonic, for a considerably lower price than an Empy/Mythic (i.e., less than half of the materials cost, and without the tedious Empy NMs or Mythic tasks). Especially shines in any non Attack capped situations with the Atk+60 and very easily maintained Atk+10% Relic aftermath. Good associated WS in Metsu, which is also really flexible for SC purposes.
Kannagi can perform well when you can take advantage of Empy AM3 (more finicky to maintain than Relic though) and a good crit TP set for white damage. Reliance on Hi makes it a bit more of a one-trick pony for SCs (Heishi/Kikoku both have better utility for light SCs), and the AGI+50 is still annoying (even though it has some niche utility like Racc for more Daken TP or higher Evasion/crit reduction through AGI). Sigh... if only Hi/Kannagi were DEX based, we'd be in business, and maybe ideal offhand like Almace/Twashtar for their jobs.
Nagi lags way behind the other three for DPS (and often even to a well augmented mainhand Kanaria or Ochu), and costs the most of any RMEA to make. It does have a couple niche BiS uses, both for roles that aren't really the job's bread and butter:
(1) Arguably best tanking weapon thanks to Enmity+40 (though lower enmity through damage will partially offset that), but in a game where straight NIN solo tanking is fairly rare these days, and
(2) Macc+40 (and the same macc skill/magic dmg as the other RMEA) makes it the best katana for enfeebling Ninjutsu, and potentially elemental (though if you really wanted to go all out on NIN elemental damage, a mainhand Ochu or Kanaria might still win depending on situation and would still give respectable melee numbers).