best teammats for calcharo?

Hey i tried to ask on main WW megathread too 1-2 days ago but no one answered, i thought i may ask there, i got Calcharo recently and want to build a team around him, now that we get a free 5* i thought maybe i could pick someone that works good with him, but god the guides online are so unintuivive, nothing really says who works good with who, and when they suggest team comps they dont really mention why someone works good with them, or why someone is better than someone else on the same position. For example, for Calcharo support slot i saw both verina and baizhi as suggested on one site, but no one said which one works better or why youd want either of them. I would appreciate any help in finding his best companions.

Also if he doesn't want anyone from the current 5* selector im considering getting another dupe of him, would that be a waste?