Anyone tried Mega Blaziken?
I tried it today. Its ability is different from what the description suggests. What it does is, if there is another Fire-type Pokemon on the field, it replaces three tiles of that Pokemon with Mega Blaziken. The tiles are selected at random. If there is >1 other Fire-type, it only selects one of those Fire-type Pokemon.
It proved underwhelming when I tried it on the Mega Heracross stage, both with just Heatran as a paired Fire-type, and with an all Fire-type team. Unlike Slowbro, the pairings aren't necesarily close to other Mega Blaziken, which means you usually don't get a combo off. You need a large amount of Mega Blaziken to get it working, but that is a slow process. Whilst theoretically you could pair off Mega Blaziken to have more form, it's usually 3 for 3, and as Mega Pokemon tend not to form right after pairing them, you tend not to get more. The main upside to Mega Blaziken is that it Mega Evolves quickly.