My favorite legendary pokemon Duo!
Mega mewtwo x vs my creation-Mega Darkrai.
Psychic fighting vs Dark, they balance out the others weaknesses.
Although Mega Darkrai's ability is called "Dream body" and when the move dark void is used it triggers a forme change that also changes its typing to ghost/dark rendering physical moves ineffective.If the move "phantom force" is used while in "Dream forme" Mega Darkrai will resort back to its regular form.