Mega Evolutions in 'Pokémon GO!': How to Make Your Pokemon Super Buff

What are mega evolutions in 'Pokémon GO!'? It's basically a way to make your primary Pokemon super buff, but you can only have one at a time.

Here's how Mega Evolution works in Pokémon Go

Revamping the Mega Evolution system

Pokémon GO Mega Evolutions List - How Get Mega Energy

Pokémon Go Mega Evolution update and new bonuses, how to Mega Evolve and all Mega Evolutions list

Pokémon Go Mega Tyranitar counters, weaknesses and moveset explained

Here's Every Mega Evolution That Will Eventually Be Added to 'Pokémon Go

How to power up and evolve Pokémon in Pokémon Go, with special evolution methods explained

All mega Evolutions and their max CP! (Source: Couple of gaming on twitter) : r/pokemongo

I'm confused, Mega Evolution story wise means there's a strong bond between the trainer and pokemon, but Mega Absols pokedex entry states it hates being in this form. How does this make

All Shiny Mega Evolved Pokemon in Pokemon GO, ranked from best to worst