Minimum stats are calculated with 0 EVs, 0 IVs, and (if applicable) a hindering nature. Maximum stats are calculated with 252 EVs, 31 IVs, and (if applicable) a helpful nature.
Mega Garchomp's Pokédex entries
Excess energy melted its arms and wings, transforming them into giant scythes.
Its vaunted wings become scythes, sending it mad with rage. It swings its scythes wildly and slices the ground to pieces.
Its arms and wings melted into something like scythes. Mad with rage, it rampages on and on.
Its disposition is more vicious than before its Mega Evolution. Garchomp carves its opponents up with the scythes on both arms.