Honestly, I don't feel like we need to see Kefka. The Warring Triad themselves are enough FFVI fanservice, in my opinion - and, even better, they help to fill out something that was kind of a letdown for me in FFVI itself. As much as I loved the game, I was kind of bemused by the fact that you wind up battling the three gods responsible for all magic - and all three of them are pretty much minor characters and pushovers to battle. FFXIV is finally giving them the spotlight that they deserve, rather than relegating them to being stooges of a madman clown.