I think whole arc with Cesare is just to appreciate Alphonso more... Thanks to Cezare at least Ari didn't marry that disgusting king. At first I preferred Cesare as ml because Alphonso deserves better. But I think Cezare love idea of stealing brother lover more than actually Ari... I don't think Ari is really stupid she has trauma from past life and Daddy issues plus probably borderline... She just wants to be loved...
I need spoilers