If I remember correctly There is a Super Genius Child (the kid could give a Heterodyne conniptions) about not quite in his Teens (still in grade school) by the name of, Barry Ween...
He does Time Travel, and the Occasional Side Universe.
Mind you the Scary one from that Series is Barry's friend/sidekick Jerry Who has a level of Acceptance of Abnormality measured in multiple digits. Not Mundanity, just that at some point he stopped reacting to things being casually weird as long as it's a relatively safe weirdness.
He does Time Travel, and the Occasional Side Universe.
Mind you the Scary one from that Series is Barry's friend/sidekick Jerry Who has a level of Acceptance of Abnormality measured in multiple digits. Not Mundanity, just that at some point he stopped reacting to things being casually weird as long as it's a relatively safe weirdness.