This being anime we're talking about, it's a legitimate question if the first two might actually have been deliberate references... or at least sneaky theft. Again, this is anime, the line between the two are thin to non-existent.
The third one, though... Okay, Batman & Robin didn't come out until the year after Slayers Next aired, so that obviously wasn't actually being referenced here. But Batman: The Animated Series, on the other hand, introduced the idea of Freeze's wife several years BEFORE Next. Yes, the original Slayers novel that introduced Halcyform predates the show... but apparently the Halcyform & Rubia depicted there are substantially different from the ones in these episodes. So, actually, I don't know. This really might have been a deliberate Mr. Freeze reference. Or maybe I'm thinking too hard.