Emberguard
Emperor
And you are flat wrong about the motivation. GBG is popular because of the personal rewards. Why do you think GvG is dying?
GvG is dying primarily because it is not on mobile (personally, GvG is way more fun that GBG...
Guild Battlegrounds only got created because GvG was popular but inaccessible to mobile. It's like remaking the same movie half a dozen times and then asking why the fanbase is into one particular version but not the other. They're competing against each other due to being so similar. If Guild Battlegrounds hadn't been created and GvG merely ported over with any tweaks necessary for mobile, then GvG would be the popular feature now.
You're right Guild Battlegrounds is popular on the reward side of things. But it was also never given a opportunity to be popular without rewards due to it being there since introduction