Extra nephenee

I pulled my third Nephenee and I'm not sur what to do with her. I fodder my second one to OG Lyn and I use my first one with decent IV(+def -hp). Was wondering what I should do with my new one. I don't have any unit that really wants Wrath except Karel, but he's rare and mine is not great iv, like +def - res or something. Should I merge or be more patient? What would you do!