Hollis (once H'lis, but he prefers his original name) and Korea, riders of bronze Synesth and gold Kalareth, are the current leaders of Blackstone Weyr. Always setting itself above and beyond the current or required standards of any Pernese era, Blackstone thrived in Threadfall, and had so many tricks up its sleeve it wasn't a good place to try and get a straight answer about how their riders got to be as good as they are.
Truth be told, they - like S'xon and Dragonhope - often would throw their riders around between times. Training either in Threadfall or out of it depending on duties, and thus even their least fight-required riders would have excellent training before they ever got into a wing.
Blackstone rests at the top (and in the whole thing) of Kshau Isle, and houses many dragons. The inhabitants have begun to spread around on the smallish isle, but enjoy all the normal perks of being riders or family. Korea is a dragon healer of some renoun, able to use her strong empathic commands on both dragons and humans. Hollis... Well, let's say that he is in many universes related to Engel, and shares many of the traits that make the Alabaster leader strong.