When Luke thought of what he should do to get stronger in that space. He realized that he had two options: the first was to train himself there and try to resist the hardships of the flow of time there. Not the usual flow of time, but the one in his head. Even if time doesn't pass in reality, he still would feel it like he wasn't making any progress on getting Aivern, at least not quick progress. The second option was to learn how to make a clone in one way or the other. Still, it was hard to say if he could get the experience of the clone if he made one that was real and made of bones and flesh. It would be a bit weird.