Dynamax

Dynamax is a special technique is the Pokémon series. Pokémon that perform this technique will grow drastically. Dynamax will increase their HP and use Max Moves instead of their normal moves. However, the Pokémon will return their normal size after a few turns. It can only be activated in special arenas or Max Raid Battles.

Mechanics
Dynamax will only last for 3 turns but, it increases their HP by at least 50%. Their dynamax level will add 5% for each stage. In addition, Dynamax cannot be flinched, switched out (except by Emergency Exit), have their ability be changed

Max Moves
Replacing the Pokémon's normal moves, the Max Moves are stronger versions but with a uniform additional effect. Max Moves bypass Protect like Z-Moves, dealing a portion of the damage. Here are the Max Moves with their corresponding effects.
 * Max Strike (Normal) - Lowers enemy Speed
 * Max Knuckle (Fighting) - Increases ally Attack
 * Max Airstream (Flying) - Increases ally Speed
 * Max Ooze (Poison) - Increase ally Special Attack
 * Max Quake (Ground) - Increase ally Special Defense
 * Max Rockfall (Rock) - Activate Sandstorm
 * Max Flutterby (Bug) - Decrease enemy Special Attack
 * Max Phantasm (Ghost) - Decrease enemy Defense
 * Max Steelspike (Steel) - Increase ally Defense
 * Max Flare (Fire) - Activate harsh sunlight
 * Max Geyser (Water) - Create rain
 * Max Overgrowth (Grass) - Create Grassy Terrain
 * Max Lightning (Electric) - Create Electric Terrain
 * Max Mindstorm (Psychic)- Create Psychic Terrain
 * Max Hailstorm (Ice) - Activate Hail
 * Max Wyrmwind (Dragon) - Lower enemy Attack
 * Max Darkness (Dark) - Lower enemy Special Defense
 * Max Starfall (Fairy) - Activate Misty Terrain
 * Max Guard (Status Moves) - Protects team from all moves including Max Moves

Restrictions
There are currently 3 Pokémon that cannot naturally dynamax. They are
 * Zacian
 * Zamazenta
 * Eternatus

Gigantimax
Gigantimax is similar to Dynamaxing except the Pokémon changes its form when it grows extremely large. Additionally, one of the Max Moves is replaced with a G-Max Move corresponding to the Pokémon's type. Pokémon that Gigantimax cannot normally Dynamax. The Pokémon that can Gigantimax are
 * Charizard - G-Max Wildfire (Fire)
 * Butterfree - G-Max Befuddle (Bug)
 * Pikachu - G-Max Volt Crash (Electric)
 * Meowth - G-Max Gold Rush (Normal)
 * Machamp - G-Max Chi Strike (Fighting)
 * Gengar - G-Max Terror (Ghost)
 * Kingler - G-Max Foam Burst (Water)
 * Lapras - G-Max Resonance (Ice)
 * Eevee - G-Max Cuddle (Normal)
 * Snorlax - G-Max Replenish (Normal)
 * Garbodor - G-Max Malodor (Poison)
 * Corviknight - G-Max Wind Rage (Flying)
 * Drednaw - G-Max Stonesurge (Water)
 * Coalossal - G-Max Volcalith (Rock)
 * Flapple - G-Max Tartness (Grass)
 * Appletun - G-Max Sweetness (Grass)
 * Sandaconda - G-Max Sandblast (Ground)
 * Centiskorch - G-Max Centiferno (Fire)
 * Hatterene - G-Max Smite (Fairy)
 * Grimmsnarl - G-Max Snooze (Dark)
 * Alcremie - G-Max Finale (Fairy)
 * Copperajah - G-Max Steelsurge (Steel)
 * Duraludon - G-Max Depletion (Dragon)