Could there be a ship scene for Yveltal where she would ask Arceus WHY she was born/made this way of being the personification of death and power of it. The response can be to be the balance to Xerneas. Then Arceus would then say that she is getting the purest form of love from the MC since he knows he could die at any time being with her but still wants her to be happy and loves her not for her power but the person she is inside and that she deserves to be a mother and has a better respect for life since she understands life can end at anytime and cherishes it.