|Arthur got perhaps his only lucky moment in his entire existence by winning the refine lottery - not only it brings him a +3 boost to all stats when he has a visible buff, but he also gets +5 to all stats during combat when his HP is below 100% or he gets struck with a penalty! This essentially turns an initially brutally outclassed unit into a behemoth of destruction who can use the massively inflated stats in order to wreck havoc on everything, while also benefitting of a leveraged resistance to Panic. As a result, he's one of the best users of Fury and its related skills, given the damage it deals every initiation, allowing him to duel most units without a problem.
Because of this, any boosting IV will work, bar perhaps HP, which doesn't directly benefit from Arthur's weapon unless you're trying to avoid Panics. Even his Resistance can be considered as a potential increase, given the superasset bringing it to an alright base 28 and improving his arena scoring. For a special choice, Luna helps him blast through high defense units he might have trouble against, while Aether is for the Arena score if you really do bother about that mode.
Atk/Spd Push or Fury allow him to get into <100% HP range after one initiation, but also offer a well-needed stat increase to him; The bump to his offenses that Atk/Spd Push offers is great, but Fury grants all his stats a flat boost, allowing him to avoid Ploy-related effects running rampant better, especially if he runs +Res.
Given his HP will quickly drop due to his A skill, Desperation allows him to chain hits and become capable of 2HKO'ing what would kill him in retaliation, while Null Follow-Up does the "Cannot Make Follow-up Attacks" in. Double Wave allows him to keep the stat increase granted by bonuses permanently while the choice of Res is both because the Odd variant is available on Aversa, a free unit, and the higher Res improves his ability to escape ploys and duel dragons.
As a reference, with that set and under 100% HP, an unmerged Neutral Arthur reaches an Atk/Spd/Def/Res of 47/44/38/38 during combat with Atk/Spd Push active (or 43/40/41/41 with Fury 3), which is certainly not too shabby for a launch unit like him. While having spent years in the shadows of the misfortune that Gem weapons are, Arthur finally gets the chance to shine he's always deserved. Congratulations on never giving up, you legendary Hapless Hero you!
Miguling (talk) 15:51, 5 December 2019 (UTC)