They have a point about the whole city thing. The main city in the Gunvolt verse, the one with the giant Sumeragi building is likely the largest in the setting, it should be comparable to Tokyo in that sense, but Tenjian froze another, different city. It did have a five star hotel, so that would mean it wouldn't be some kind of pathetically small town.
Again, Tenjian freezing it in parts was already debunked beforehand, which is why it was calced in the first place. But, he did freeze the stage in parts, but that was only the second part of the stage, and the second part of the stage takes place inside the hotel. Tenjian "covered the city in ice" meaning that he would only affect outdoor places. Also, he froze the parts of his stage in his Non-Grimore form, presumably, as his dialogue box where he speaks before freezing the first part was shortly afterward had him in his normal outfit, not weaponized. Same can be said for Milas, who does have presence throughout the stage in the same manner.
But in the event that this isn't allowed somehow (even though I believe we accepted it a long time ago), Seven Slashes, his ice crystal dash thing, and Frigid Blossom.
I'm getting really dang tired of this perpetual loop