Sonic Doctor said:
Why wouldnt you? Flareon gets access to wish. The standard Vapreon is a sp. atk tank that runs a wish, surf, ice beam and toxic set with high HP and Sp. Atk. Its a huge sp. atk hit.
Now, if you could give that to Flareon, then you get a move that, with guts and a life orb, as well as a STAB move that works off its stat strength, could bring down pokemon in one hit that are even neutral to fire. Giga Impact makes you wait a turn to attack, and has 5 PP. Flare Blitz has 15 pp, 120 power, 100 accu. and STAB.
Right now, Flareon's strongest STAB attacks are both Sp. atk. One being Fire Blast, 5 pp, 120 pwer, 85 accu. the other is Lava plume with a 15 80 100 spread. Both working off base 95 Sp. atk stat that in you have to sink Precious EVs into to make thm work to their full potential. With flare blitz, you could run a wish, flare blitz, (possibly) toxic, and superpower set, which could sweep through teams.