This answer assumes the question was asking about VGC Regulation E or Doubles OU. Please tell me if you're asking about something else
Charizard is currently unviable in both VGC Regulation E and Doubles OU. Its 109 special attack and 100 speed might look impressive, but there are still many better options that you're allowed to use. If you want a fast offensive Pokemon, Hisuinian Arcanine, Zapdos, Tornadus, Chi-Yu, and hearthflame Ogerpon all have much stronger offensive stats, and all of them besides Zapdos also have better abilities.
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