Cordelia vs Shigure
Does anybody have concrete evidence (such as experience) on who's better with firesweep + heavy blade + QP combo? Intuitively I want to go with Shigure because 44 spd (Cordelia +spd with hone fliers) doesn't feel so convincing these days while 54 (after hone fliers) is still decent for activating heavy blade and he's very probably doing better if additional buffs are in play.
Even if you only play one of the two, if you're using firesweep lance I'd be interested to hear from you
EDIT: 54 atk, in case I confused anybody.
Shigure is the better Firesweep user since speed is the most important stat (unless it's an unorthodox Bold Fighter build or something).
+Spd/-HP Shigure, with Hone Fliers buff, has 54 attack and 46 speed.
+Spd/-HP Cordelia, with Hone Fliers buff, has 56 attack and 44 speed.
While Cordelia has more attack (really isn't that much more), Shigure has more speed which is vitally more important for a Firesweep Flier.
The problem, however, is that both struggle with proc'ing Heavy Blade reliably due to how high the attack stat can go to with higher-tier Arena units.
Too bad they can't use Flashing Blade seal. :l
As for who is generally better (assuming generic IV"s, IE neutral) Cordelia is better balanced (35/35 in atk and speed) while Shigure is faster at the cost of more damage (33/37) I myself would go with Cordelia for the build since I've had that build for some time, and I can say she performs the part all too well, with a fair bit of leeway on skills. Shigure would need an atk boon (to reach/pass cordi by 1 point) while cordi could work with either (38/35 or 35/38, her choice) so overall, she performs "better" due to more optimized offensive stats, while shigure works well on offense, but prefers his harmonic lance due to the extra damage it nets him on specials (which helps his 33 atk)
I really think that because you're throwing heavy blade into the mix, the attack stat will take priority over speed. As such death blow or swift sparrow for more scoring weight will be your A-skill. In a flier emblem where mobility is their best asset, positioning fliers as such where your FS user can receive a maximum of 3 goad buffs, speed will not be an issue.
Personally, I like the slaying weapons better for a Heavy Blade build so I can use something else in the seal. My favorite set-up is spd slaying+gale force+swift sparrow+desperation+heavy blade seal, which does so wonderfully on my NY Camilla.
+spd Cordelia user here with Firesweep. She's +8 with Swift Sparrow + Heavy Blade, and I never had any trouble activating Galeforce (58 atk on initiation before buffs).
I also have a -hp +spd Shigure, but I find him more suitable for his native weapon due to better defense for melee brawling. Plus, Cordelia is the better Heavy Blade user due to having 2 more attack.