Shadow Charizard

Shadow Charizard boasts strong offensive power. At the time of its release, it was one of the best Fire-type attackers in the game, and is currently still genuinely pretty good. While its fragility may cause less Total Damage Output (TDO) than other Fire-types, proper dodging can help to mitigate this problem and ensure Shadow Charizard stays in the fight longer to deal more damage. As time goes on other Fire-types are expected to get their own Shadow variants, but until then Shadow Charizard is a great option. 

Best PvE Offensive Moveset

• Fire Spin is Charizard’s best fast move and strictly superior to Ember.

• Wing Attack is preferable to Air Slash, and should be paired with Air Cutter for Flying Type damage.

• Blast Burn makes Shadow Charizard one of the stronger Fire-type attackers.

• Overheat is Charizard's best non-exclusive charged move and beats Fire Blast soundly.

• Flamethrower has less cycle DPS than Overheat and is just a worse Blast Burn*.

• Dragon Breath and Dragon Claw can work as a pseudo-dragon attacker, but are best reserved for Mega Charizard X.

Best PvE Defensive Moveset

• Attackers may be inclined to throw Water-types at Charizard, in which case Air Slash edges out Fire Spin.

• Ember and Wing Attack are worse versions of Fire Spin and Air Slash, respectively.

• Dragon Claw is the preferred charge move due its early damage window, wide neutral coverage, and 3 bars, while Air Cutter grants additional chances for Flying coverage.

• Flamethrower is a decent alternative, but Blast Burn* is decisively better.

• Fire Blast and Overheat are poor due to their late damage windows and charge time.
• Dragon Breath is inferior on defense.

Charizard's best Fast Attacks are both Elite moves. Ember provides the highest energy gains, while Dragon Breath sacrifices a small amount of energy gain for more damage and coverage. Both are excellent options. Fire Spin, Wing Attack, and Air Slash all pale in comparison.

Blast Burn is what makes Charizard so devastating - its tremendous DPE makes great use of the high energy generation of its Fast Attacks. Air Cutter's cheap energy cost provides Charizard with a bait move, which can make its opponents's shielding decision difficult when paired with the lethal damage of Blast Burn. Dragon Claw is a little too expensive since its rework. Overheat is strong, but the Attack debuff makes it not worth using, especially since Charizard is more than powerful enough with Blast Burn. Flamethrower is strictly worse than Blast Burn, and Fire Blast is plain horrendous due to its immense cost.