no more caves!
and i still dont like the idea of them being resurected from a fossil:
one the bones are all mixed up and we cant tell what it really is
and two- if the pokemons of yin and yang were either both dead or one of them was dead, then wouldnt the universe be in chaos?
my opinion= the bones are that of the third box legend who is either dark/dragon or ice/dragon or grass/dragon, this legendary is the pokemon of chaos and team plasma wants to revive the pokemon of chaos who was defeated by the combined powers of zek and resh a thousand years ago(give or take, just an estimate) and use the chaos dragon's power to make reshiram and zekrom(who are the only ones who can defeat team plasma) fight eachother, distracting them, so they can use the power of the third legend and/or the crown artifact, to free trainers pokemon. and in the final battle against tp, you can only use the version mascot to fight the chaos dragon, because your own pokemon have been temporarily released