In my honest opinion, I think this ship didn't work much as the two characters to me, didn't have much interaction that I feel is necessary to build some sort of relationship.
I think even these two had never really had a true conversation nor do they really know each other.
So, the real flaw of these ship is simply nothing or not much to work with.
I can only imagine their relationship and even fanart only shows the more antagonistic side of their relationship.
So, I can't say it's that good but I also got curious about this ship for the fact that Yuri and Serena kind look like Yusaku's parents in a lot of specific ways.
Yusaku has Serena's blue hair colour with Yuri's pink hair colour and he also has Serena's eye colour. So, this idea I think is actually fun which is why I would like to try out this ship.
It's growing on me.
But tell me what you think personally.
Honestly, I think this ship exists because everyone wants to ship the Zarc Counterparts with the Ray Counterparts.
Also, do you think the counterparts are like the children of Ray and Zarc or more like sisters and brothers?