>>463974791. Xerneas is a box legendary and shouldn't be held to the same standards as normal mons. It's okay for them to be broken.
2. Even if it wasn't okay, Xerneas is a broken sweeper, rather than a broken wall. At least the battle is over soon, while Toxapex prolongs it forever. Hence my wording of "most cancerous" instead of "most overpowered" or "most broken".