Pokemon Team Valiant: Return to Azure
We did see a mega blaziken at the fortress while we were being evacuated, but at the time we had no idea that it was volcan. grom didn't tell us he'd come to rescue us. this further fueled the growing resentment we already had for him.
Sands of the West Chapter 6: The Way Home
A bright glowing light behind him and his partner silenced him, and they both looked back to see volcan, having activated his mega stone, the arms of the mega blaziken crossed over his chest as he glared at the three henchmen. "try it.
Beyond the League: Chapter 12
"so that's a mega blaziken?" brock asked, keeping a calm composure as he watched. "sure is, pal," replied randy. "i did not get to see blaziken's mega evolution when i battled mark," commented lance.
Battle for Hadleigh Chapter 8: The Siege of Hadleigh
Her six followers, so caught off guard by their leader's sudden removal, realized their mistake too late as bright lights from the group blinded them, and then a mega lucario, mega blaziken, and mega lopunny charged into them.
Chaos Chapter 14: Break (True Epilogue this time)
Volcan had been wearing the form of a mega blaziken. it seemed grom had also not informed them that it was him there that night, to keep his story of volcan's 'selfish cowardice' consistent.
Sands of the West Chapter 4: Crossing Paths
Volcan and luke stared down the three thugs, who were visibly intimidated by the mega blaziken and mega lucario they were now faced with. volcan cracked his knuckles as he spoke to them, bearing a hint of malice in his voice.