for madan (魔男) its just replacing the 女(woman) in 魔女(witch) with 男 (man) instead. So translating it as male witch or magical boy would make sense. warlock is an entirely different word, while it still means male witch it makes it sound it like there are other cases that made it necessary to have...
tbh it makes sense to me. theres no male witches so there wouldnt be a specific word for them either. It just seems like a title thats hard to translate properly.