Okay hear me out,

Not an original concept, but was having fun thinking about and tailoring it. Saw a video thumbnail about how to not to introduce character powers with one saying over powered and the other one saying plot holes.

And so I was like, how would I introduce a super powered characters powers?

That lead to me thinking up a sort of X-Men setting character who when they're around you, the audience, and the other characters might notice some inconsistencies and see some things sorta just jump in or out of place, like disappearing, reappearing, staggering. Like if someone dropped something fragile, but you never hear it hit the floor cause it's on the table next to you or the last soda disappearing right as you open the fridge and you see him halfway through a bottle of the stuff that you didn't notice he had before.

I feel like that would be good for hinting at the power while not showing off too much. And then a full reveal of what's going on and how he's doing it later when it really counts. By the major encounter scene the newer characters to the group and audience who haven't seen him go all out assume he's not a fighter type of ability, but he's there in his gear anyway but hyperventilating with shallow breaths for a long time which makes them assume he won't be much help but when the doors open for the fight everything stops.

Then you only see him moving calm and collected with efficient measured actions to reduce energy consumption while incapacitating enemies. Slashing throats, slicing ankles, and jabbing hard to aim for weak spots and openings in armor that would be hard to get while in motion. And then when the first room in fully cleared of the starting defense of their opposition, he finally releases his breath and time resumes, revealing that he can stop time for as long as he can hold his breath.

I wanna say he's born adapted for the ability, with him being able to get a good 9-15 minutes on a decent normal to deep breath depending on the amount of movement and energy he's expending, making him need to take another breath sooner, his body would be able to take in and hold more air and use the oxygen more efficiently but needing to breath will be inevitable. But to help extend it in more extreme cases he'll do free-diving hyperventilating techniques to blow off CO² and hold his breath even longer than usual. I imagine it like a sort of speedster/quicksilver kind of scene but without needing to worry about momentum and whiplash but instead oxygen levels and making sure his blood doesn't get too acidic.

I know the time-breath hold is a classic hypothetical in would you rathers, but I feel like there's easily more that can be explored there since people usually only talk about it surface level for a couple of minutes.