I ABSOLUTELY hate both moves. I hate them so much I would get a Shuckle and make my Shuckle fart on Fire Blast and Blast Burn until they die. Fire Blast is available to far more Pokemon than Blast Burn. Only 4 Pokemon learn Blast Burn (Charizard, Cyndaquil, Quilava and Typhlosion.) I can understand people liking Thunder, Hydro Pump and Frenzy Plant. (Thunder has 10PP rather than 5, 30% chance of paralysis and 100% accuracy in rain (even though Thunderdancing does not work), Hydro Pump, has 80 accuracy opposed to 70 like Thunder, Fire Blast, Blizzard, etc., powers up in rain and it is used in double battling because Surf is rather useless and Frenzy Plant is good on Meganium and Venusaur because they do not have many good grass moves, Frenzy Plant does more than 2 Hidden Power Grass anyway and Venusaur and Meganium can survive and heal themselves if they take damage on the recharging turn (or they could put their opponents to sleep while they use frenzy plant)). I do not suggest any of those moves (or Charizard he is TERRIBLE (Shuckle is also terrible but he is a favorite of mine for other reasons)). Do NOT use them. (Use Flamethrower and use Charizard to dragonthrow if you desperately want to use him.)