Hi,
I have been thinking about serperior for a while but I fail to see the benefit of not using 4 royal heal ones.
If you heal for 20 with your attack, everything but reuniclus, that's fine but if you have a royal heal instead you will heal 10 when it goes to your opponent then 10 again when it comes back to you making it the same 20 as well and affecting reuniclus and move your energy around if needs be.
Granted 10 of these damage comes after your opponent next attack but it should not be a problem. Working from the bench and healing reuniclus outweigh that little drawback imo.
I also have only been thinking about it in a HGSS-on format.