Pairing my single Banggai Cardinal.

So I have a single adult Banggai Cardinal that I would really like to pair, but I am unsure of how to go about it. I originally had two, but one ending up getting sick and dying from a disease outbreak soon after introduction (that is now taken care of). That was about a year ago. Recently I bought a little tank raised banggai in hopes of it growing and getting a pair, or at least a couple individuals that would get along. However my current one chased it off and my blue jaw trigger decided to make a snack out of the poor thing so I wasn't able to find out if the aggression would get better. So I am wondering what to do now. It doesn't seem as simple as pairing clownfish, and it's not helpful I don't 100% know the gender of my current one. Should I buy another baby or two (the triggerfish will be taken care of in the mean time), or should I try to find some adults? I guess however if in the end if nothing works out it's fine. I just like seeing these fish in pairs. Thanks.