As long as Machamp is your Active Pokémon, each of Machamp's attacks does 60 more damage to the Active Pokémon (before applying Weakness and Resistance) and any damage done to Machamp by your opponent's Pokémon is increased by 60 (after applying Weakness and Resistance).

During your opponent's next turn, if Machamp would be Knocked Out by damage from an attack, flip a coin. If heads, Machamp is not Knocked Out and its remaining HP becomes 10 instead.