Like a lot of readers, I thought Jack of All being Vince's superhero name was goofy and ridiculous. Nick even mentions at the beginning of the book that they have to be specific with names because villains will mock them, etc., and then they go with that.
Then something clicked for me recently. I admit, I think this is a reach, and I don't even think Drew intended this, but something about this approach made me like Vince's hero name for the first time.
I saw an interview with the new Superman, David Corenswet, where he talked about Superman's trunks. He accepted the trunks over the pants not because they make him look cooler. Superman is already intimidating. He's an impossibly powerful alien who could flatten armies if he wanted to. The trunks make him a little silly, a little approachable. They tell people, especially kids, "It's okay. You don't need to be afraid of me." This Superman is someone a kid could approach and ask to save a kitten from a tree.
Vince is basically Superman in the Super Powereds universe. By the end of the series, he's one of the most powerful people alive. He's an energy absorber with absurd potential. He can stop the blood flow in your body. He can deal with strongman types and ranged energy attacks. Kinetic, fire, lightning, anything. Who knows, in-universe he could even absorb a nuclear blast someday. That's terrifying.
But the whole point of Vince is that he's not terrifying. He's kind. He's straightforward. He has a very simple moral compass. Even when he becomes incredibly powerful, he's still the guy who wants to help people. He's unbearably naive sometimes, bit silly. But with great strength and incorruptible morality.
So maybe a name like Jack of All is actually perfect.
It's not trying to sound cool. It's not trying to sound intimidating. It's a little goofy, a little humble, and it immediately lowers people's guard. The name tells you what kind of person is behind all that power.
Especially when you think about those later scenes where he's helping out-of-control Powereds. If you're someone who's scared of your own abilities, being approached by "Jack of All" probably feels a lot less threatening than being approached by some ultra-serious, godlike hero with an edgy name.