There hasnt been an Emote made for any rank after 12 (and it hasn't been a long time since they added the rank twelve emote).
And noone is rank15 to find out any of that information anyway.
The highest anyone has at the moment is Rank13 (Emperor's Hero). And thats just a handful of people, if that many.
But if the points needed scales the way it does now you'll need ~100,000 fame to get rank15. Because its 21600 for rank12, 36000 for rank13, so the scaling would make it ~60000 for rank14, and ~100000 for rank 15.
BUt noone knows yet.