For tabletop characters:

-- Ilphyl will mess around with it, but isn't actually trying to solve it.

-- Bel will learn how to solve one, but take them apart and reassemble them on general principle. Potentially after solving one.

-- Shakudo is more interested in how they are constructed.

-- Isk would, and probably make some comment about how kobold puzzles are more intricate to test mechanical aptitude.

-- Helen learned but is also one who uses things like that as fidgets. Unlike Bel, she doesn't take them apart to be an asshole.

(Between a wizard, a rogue, a smith and a gadgeteer in a supers setting, I have a lot of characters who might know how to solve a Rubiks cube.)

Other tabletop characters: Gretchen might learn as a party trick, but only if someone dared her to. Constance and Chel wouldn't care.

For DWRPG, Zelgadis might as some weird skill he picked up. He might even be able to do it without looking, if Rezo was the one who built it (in which case, the markings on the cube would be raised numbers or something, not colors).

Penric might learn, but Des would probably break them if she got bored or they needed to burn off some chaos. So more likely to carry intricate mechanical puzzles for 'hey, entropy sink'.

(Trying to think who I normally play in memes...)

Lafiel could solve it but would get frustrated that she can't solve it immediately, I bet

Jinto gets hit by one thrown in frustration

Sounds about right. Especially if she was just handed one and expected it to be easy. (And probably gets annoyed when she learns there's an algorithm.)