Nick Castellanos has one of the most beautiful minds in baseball. It's as pure as the day is long. His brain hasn't been soiled by higher education. This is a man who once famously said, "I don't have a college degree. I hit baseballs". It allows him to be a free thinker. A man who feels no need to abide by conventional wisdom.
So while conventional wisdom would lead you to believe that superheroes are just the characters you see in Marvel and DC movies, Nick Castellanos fancies himself as more of a Scooby Doo guy. And if you don't think that Scooby Doo is a superhero? Well you're dead wrong, bub. And Nicky Baseball is here to prove it to you.
Point 1) He's a dog who can talk. Seems pretty frickin' super to me. How many other dogs out there can converse in fluent English with humans, albeit with a bit of an impediment. You've got Brian from Family Guy. And I could be missing another here but I'm pretty sure that's it. Think about how many superheroes can fly. Practically all of them. The fact that there are only 2 dogs in existence who can speak to humans is a wildly more exclusive superpower than flying.
Point 2) He solves mysteries. Brian from Family Guy can speak, but he sure as shit ain't out there solving mysteries every damn day. Hell, it took the Avengers like 7 whole movies to figure out who to stop Thanos. Scoob would have wrapped that shit up in about 22 minutes before you even finished your bowl of Frosted Flakes.
Super power. Heroic actions. Nick Castellanos drove that one deep into left field. Scooby Doo is officially a superhero, and it's time for Disney+ to give him a new series to solidify it.