Latios

While Mega Latios competes with other offensive Psychic-types like Mega Alakazam and Tapu Lele, it sets itself apart from them with its Dragon typing, access to reliable recovery, and Levitate ability allow it to provide a consistent check to Pokemon like Arghonaut, Volkraken, Heatran, and Landorus-T. Its additional resistances and access to Recover also make it a lot easier for Mega Latios to switch into play, and thanks to this, it's very durable, unlike Tapu Lele. It further distinguishes itself from other Psychic-types like Tapu Lele and Mega Alakazam through its access to Earthquake, which allows it to consistently deal with Steel-types like Heatran and Magearna. However, it tends to struggle against other Steel-types like Celesteela and Ferrothorn, which Mega Alakazam and Tapu Lele can overwhelm over time with Focus Blast. Additionally, it's prone to getting Pursuit trapped by Weavile and Colossoil, as well as by Mega Tyranitar to a certain extent. Furthermore, Mega Latios struggles to deal with Fairy-types like Jumbao and Tapu Lele.