Lucario

Lucario are very reserved, prideful and very serious Pokémon and also extremely loyal to their trainers, but they can be also friendly and cooperative with strangers and their Pokémon. According to Gurkinn in "The Aura Storm!", when a Lucario Mega Evolves, the power of their aura and their battling instinct is brought to the limit, so much so that when in battle a Lucario only focuses on their opponents. When a Lucario loses control of its aura in this stage it'll go wild, berserk and relentlessly attack them. In the wild, Lucario live in packs and they are primarily carnivores, though domesticated ones can be seen eating plant based foods as well as other human food such as chocolate