Brave Ephraim: Merge or Fodder?

Hey all,
I recently got a second BE (+def -hp compared to my neutral one), which is great, except I already gave Aether to my first one.
I was wondering - should I keep one BE around for inheritance of his good skills (if so, who would make the most of them?) and just get another Aether user, or should I merge to +1 and get Aether on my better BE?
Thanks in advance!