-SPD +RES innes

Innes as in Normal Innes? If so make him into a mage counter since he has pretty good res.
Guard bow+DD or Nidhogg+DD( he will get more bulk and atk/spd if he is positioned properly) and def ploy
if the new Innes then brave axe or Slaying axe with +spd refine to patch up that bane and give him fury ( this build is pretty basic)

Not ideal but you can either save him in case you were going again or fodder the feint skill or rally atk/def.
If you want to use him one way to cover up the bane is fury 3 and slaying axe speed refine. 26 res and 33 def isn't bad and his 37 base speed is high enough. He'll end up being a bulky fast duelist, even stronger if you have access to emblem buffs. Hope that helps!

If I'm going to assume he's summer Innes, you can still use him.

His 34 speed is still pretty high. Give him fury and maybe a speed seal.
Something fun you could do is this:
Slayer Axe (def)
Bonfire or aether
Fury
quick riposte
-
close defence

to make him a mixed tank against melee units and dragons.

Mages are getting ridiculously fast these days anyways. Use him with native weapon, QR, spd/res bond if you're rich (otherwise darting stance or plain old fury is fairly good), distant def seal (or spd+3 if someone else is using it) and plant him next to a teammate who carries spur spd spur res or double spur spd to bait some mage. You'll block the double and KO easily with QR; his attack is quite strong especially with a 14-mt owl weapon

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EDIT: summer Innes, you meant? I don't like the IV, but 33/34 is not bad, especially for a flier, especially with his weapon. Just build him normally, stuff like swift sparrow, fury, or brazen atk/def