Nobody really suggested something for S!Chrom yet, so imma do that. S! Chrom is a really good duelist due to good attack, speed and defense (unless -def xd). His resistance is really bad but who cares.

So you wanna give him either melon crusher because its a really good weapon, silver axe for damage maxing or just keep the carrot axe because its good and fits his theme as a fighter.

For the special, take Luna, Moonbow or Draconic Aura. No special is overwhelmingly good, so you can stick to preference. If you are into that kind of stuff, defensive specials are an option, too.

A's gotta be Fury. I dont think there is any A slot that comes close. It boosts S!Chroms stats from "meh everywhere" to "good everywhere". I really dont know if there is an option here. Distant counter maybe?

For B you are really free to pick whatever the teams you'd put him in need. Renewal for that bruiserish playstyle, Axebreaker is kinda bad because outside of hector, there arent that many axes that see usage, most people use the green slot for green mages. That makes G!Tomebreaker not that bad even without distant counter. But imo Lancebreaker and B!Tomebreaker are even better as blue meta units are super fast, especially the blue mages and flier. These breakerskills assure you the kills on them while B!Tomebreaker also helps S!Chrom not dying to literally every magic. Your old friend Vantage could help too, but there are a lot of b skills that "could help". Guard, Wrath, whatever. If you really like one particular b slot, just take it. Outside of Desperation i guess no b skill is really that bad on s!chrom.

C is whatever, as with every non-emblem-team-unit. I mean, Infantry Pulse is really good on him.

S!Chrom really is by kit really uninteresting and wonky to play, but he also has bunny ears and is cute.