How would you build a +Defense -Resistance Male Robin?

His resistance and HP are not high enough to run a Ploy skill so the C slot is flexible. I left it Spur DEF to be cheap but it can be whatever buff the team needs most. On his own I suppose Threaten ATK or Threaten RES would do alright but, personally, I don't like their range so I rarely use them.

For his A slot... I think the new seals open up the possibility of running Blárraven+ without Triangle Adept. For one, Fury 3 alongside the Distant Defense 3 Seal would allow him to remain very effective against archers while giving him more general utility. Alternatively, there's always Close Counter which also seems far more viable now that Seals can be upgraded. Fortress DEF would be another option if you were more interested in burst damage than regular...but it seems like a waste of his decent offenses unless you had some sort of support (like Infantry Pulse). Sadly, Steady Breath is melee only as it would have been fantastic on him...I suppose Steady Stance would work alright as well but, personally, I'd probably stick with the more available Fortress DEF to avoid sacrificing a Black Knight.