Oh, man. He would try his damnednest to leave her alone while still being there for her, because he would want her to have the space to be her own person. But it's ESTELLE, either she would follow him around like a puppy or he would follow HER around like a puppy completely unintentionally and anyway he would probably talk about her all the time and would trip over his own dere constantly. He would introduce her to Elliot and Vincent like immediately and just be so ridiculously fucking happy that they were even in the same room. Anyone who hurt her would be fucking shanked. If she got got a boyfriend/girlfriend Yuri would be very happy for her and tease her and be RAGINGLY JEALOUS AND TSUN INSIDE OH MY GOD.

This would also be an auto-pass to Party Leader Mode because he is not going to be fucking around getting emotional and making mistakes when he has Estelle to take care of.

What happens if Ada shows up?