Pokémon Red Version, Blue Version, and Yellow Version - Last move used
Each Pokémon in battle has a "last move used" , which is the last move that the Pokémon chose for use and was not prevented from being used. Mirror Move, for example, depends on the "last move the opposing Pokémon used." When a Pokémon leaves the battle, the "last move the opposing Pokémon used" and "last move user used" are reset to zero.
In Pokémon Red Version, and Pokémon Blue Version, Pocket Monsters Green, and Pokémon Yellow Version, for two-turn attacks, the move is considered the "last used" only when it’s used on its second attack segment.
A move that can’t be used or chosen for use because of an effect can be successfully used by use of Mirror Move.