Sounds kinda like "Ben 10"? There are a few reboots of the show but I'll link the OG show's Wiki article. You'll find them all anyways if you just search up Ben 10.
https://en.wikipedia.org/wiki/Ben_10
If I'm right then the "Gauntlet" is called the Omnitrix, which is some alien watch that let's him turn into alien beasts like 'Four Arms', 'Alien X', 'Heatblast' or 'Diamond Head'.
The girl might be Gwen, his cousin, who in the first show is raised alongside Ben by their grandpa, Max. She has weird pink power blast powers. The other guy might be OG rival, Kevin Levin, who in the OG show hated Ben and was some bad boy with powers to absorb other things or powers. In the reboot where they're all older, they become friends.
The show overall follows Ben and Gwen, living in their Grandpa Max's RV, just tryna live life, but then a comet hits nearby their camp one night and Ben unwillingly gets bound by the Omnitrix. He then discovers its powers. Every episode then goes on as other weirdo alien bad guys attack, Kevin Levin shenanigans, and overarching plot that the main villain is the evil ctopus looking alien overlord, 'Vilgax'.
Here's the Omnitrix as it looked in the original show, it changes appearance slightly in the other versions but the green hourglass in black circle centre part stays the same. It's not exactly 'hexagons' but it does the same as your question's Gauntlet.