Exalted Chrom

He already comes with Chill Def. You can keep that as a budget option, or if you make his Spd go high enough, you could run Desperation. You could even ignore his Spd and go with Brash Assault on seal and Desperation on B.

This is what I'd do (I did this for my Exalted Chrom some time ago). He's the ultimate brazen master with that sealed Falchion, so I had to run this. Makes him super hard to kill when he has his Atk at such insanely high levels.

You could go two ways for him, both are fine.

Enemy phase (the easy way)
Base kit, with quick riptose as B, a horse or wave skill as C and close def as seal.
The close def will help, since he runs the risk of getting oneshot by dragons if he tries to bait a red or blue one.

Player phase (Hard, but big payoff)
Desperation as B and Brash assault as seal.
And probably Brazen atk/def with bonfire and reciprocal aid.
It takes some set up, because he'll be weak at high hp.
But once he's below his skill threshhold... Ohh boy will he kill. No dragon can survive that, but even a lot of green and red units will be dead meat to this man.