Completely engrossed in the process, Lex did not feel the hours pass him by. On his own he was learning a lot, and not just about fighting with a sword. Back on Polebitvy, when he had fought off those insects, his hand to hand combat had improved tremendously fast, alongside his sense for fighting as well.
Now, with a weapon in hand, he was learning how to manage that additional weight while keeping in mind the lethality as well as limits of the weapon. After all, for his body he had an innate sense for what it could tolerate and what it could not. For a weapon, he had to keep all of those things in mind. For example, using it in certain ways would make it more prone to breaking regardless of how well crafted it was.