Shyvana > Ao Shin > Aurelion Sol
Keep in mind these are comps you should be pivoting into given the opportunity to cap out your board and not comps you play from the get-go.
Shyvanna is the best option followed by Ao shin with Aurelion So being the weakest option (though positioning matters a lot as well as itemization and augments)
Here is a different varation of shyvana (assuming you have scortch) :
Here is an example of what the other dragon boards shoud look like :