>>23298811Megas should be reworked to be less formulaic
The requirement of a Mega Stone and the result of a net +100 to BST is too inflexible to be balanced, it excludes some weaker fully evolved Pokémon from ever getting a viable Mega while more powerful Pokémon that get Megas become overpowered.
More conditions like certain move requirements rather than a Stone and stat changes suited to the individual Pokémon would go a long way to making it a more balanced mechanic.
Though I will say most of the weaker Pokémon I'm talking about would benefit at least as much from an ordinary evolution.