A slightly more optimized version of a physically oriented mixed CharX could definitely work, much like mixed Infernape back in gen 4. Overheat is still really damaging despite the BP nerf, and after the drop in power the user can simply switch to its equally damaging physical moves. Sadly, such a set would only be useful with support and for wallbreaking due to a rather pitiful base speed(100 is not really that bad, but there are too many things that can outspeed that), which in such case you might be better off running something like Kyurem-B or Salamence, or hell even Mega Garchomp.
Of course, the mentioned Dragon Dance could patch up the speed problem, so a mixed DD set meant for sweeping first and wallbreaking second probably has a lot more potential. Something like...
Mega Charizard X
Hasty\Naive Nature
252 Speed, 252 Attack, 4 Special attack EVs. Can be optimized for getting key KOs by dropping some attack for special attack, depending on how the metagame shapes up.
-Dragon Dance
-Overheat
-Dragon Claw\Outrage
-Earthquake\Flare Blitz
It's basically a combo of the two sets mentioned above. Thoughts?