These sounds like some fun plot devices. I especially like the part about him taking their panties. I'm guessing that leads to a lot of scenes of angry girls coming back to collect those lost unmentionables along with their modesty with their fists.
Well, the first time it happens, nothing really comes of it. He's surrounded by this fantasy world's equivalent of special forces. Because it's a lewd show, they're battle maids. If I remember right, the dude basically says, "you can try and fight me or chase me, or you can take these back" and then he just throws them all into the air and disappears as they all realize he yoinked them off of their asses without them noticing. I do think it happens again later with different people; I think one was like an honor student at the weird battle academy they go to, or the class president or something, anyway she was supposed to be really good at fighting or whatever and does pretty much what you described. (The basic plot is that loads of people get Isekai'd to different worlds and come back with special powers, and it happens enough that schools are set up for them and they basically decide how strong countries on earth are. He's one of those people that got isekai'd and came back with powers. It's been a while since I watched it though, so I can't remember everything perfectly, so I don't remember what exactly she was. ) I think there's even a scene where she gets mad that he didn't take them this time, cause she bought hotter ones. Pretty sure I remember her saying she bought hotter ones at least; I think it was a tsundere "I didn't buy them for you" type deal. He also does some other weird stuff, like he can make people's tits bigger by massaging them. Not in the "increased bloodflow leads to growth over a few months of regular rubbing" sort of way, but in the "I'll grope you once and you'll gain a cup size for a while" sort of way. It's basically magic, but I remember the show being very distinct in that what the main character does isn't technically magic, but something else, and that's why he's comparatively OP. Everyone else pretty much only uses magic, and magic has certain limitations, but he does the other thing, so he doesn't have those. I think one of the big differences was where the energy for it comes from or something? Like with magic you use the energy around you, so if something uses it all, or keeps you from accessing it, you can't use magic, but his stuff is powered internally or something, so disabling magic doesn't actually keep him from doing stuff. It's been a while, so I could be wrong, or confusing it with something else. I think another difference was what exactly you do, like loads of magic is elemental, like fireballs and lightning and shit, but his thing is mostly like buffs and internal stuff. The panty and boob-biggering were definitely this show though.
There's also this weird scenario where pretty much everyone thinks he's in an incestuous relationship with his sister and they're all fine with it. She isn't actually his sister, they aren't related at all, but everyone thinks that they're siblings for plot reasons. I mean, the two of them know they aren't related, but everyone else thinks they're full blood, biological siblings. It just stuck out to me because of how fine everyone was with it. Like, "he's full on massaging his sister's bare tits in this changing room, that the three of us are in for some reason, nothing weird about that" or "Yeah, he's just tongue kissing his sister". Like, other shows that do the whole pretend family deal usually make a big deal about that sort of stuff. That or it'll be the opposite situation, like, they'll be related, but everyone thinks they're lovers cause they act like it and never told people they're related. It's just kinda uncommon to see everyone thinking they're related and not caring.
Oh, and because this is technically a Queen's Blade thread, to stay on topic I'll kinda describe the references to it I can remember. One character is from a fantasy world, so she'd never seen a TV before. So she eventually sees a TV and starts watching; eventually she starts watching QB. If I remember right, it was one of the bits with Holy Pose, and I think a beach? it's been awhile. Another time there's a dream, and characters from this show are in costumes from QB. I think they're acting like they're the character's they're dressed as? It's been a while. I think there was some kind of slime or plant monster? I need to rewatch the show. I'm rewatching all of QB at the moment, but it'll get put back on the list.