You don't. I just didn't want to redo spheres (he's on my arena team) and told myself it was because of his BC gen. Also Exvehl was already on my team in that slot. Laaaazy. Ex is a good unit and Melc is alright. Easy to spark with so doesn't matter.didn't really need the status null i think? not sure the only battle that lasted longer than 2 turns was zelnite
I did swap them for SGX and Darv for when I run terminus though.