Amid all the cards being spoiled on the mothership and elsewhere, it's easy to miss the small hints that are semi-officially dropped on magicthegathering.com, but this rumor season, just like every other, they are indeed happening. For instance, in the mothership article on the Magic Online prerelease and release events for Born of the Gods, reference was made to a previously unknown character: Brimaz, King of Oreskos, who appears to be a Leonin, and who will be the event participation avatar for the MTGO prerelease.
We don't know much of anything about Brimaz yet, considering his name and artwork have never been seen before, but it's safe to assume he's going to be a big deal - probably a white mythic legendary creature. The artwork shown depicts a massive Leonin, with a grizzled beard and frankly awesome sun-like crown, with battle scars, heavy shoulder armor, and a royal purple cloak.
There's a fine tradition of legendary sapient Cats in white, and hopefully Brimaz will be a worthy addition to this. As for his abilities, he definitely looks defensive, but also capable of handing out a beatdown on the offense - perhaps vigilance, and granting your creatures +1/+1 counters for blocking?