For people wondering how he got here, he can switch place with a shadow and had one in the dad's shadow. ALso he didnt give him directly because he didnt know if he was really sick or not. And he doesn't have an infinite amount of it. And i have to admit this one looked rushed, but if the fight later aren't, i'm fine with it. If you want the blabla you can check the light novel
@Ratentaisou no its about right its just how long this story is that it made it feel super short he didn't need to do any challenges because he already had the potion lol
For those wondering I believe the reason he didn't do it sooner was partly because he didn't want it be known that he has a way to cure eternal sleep due to the fact that he can only do it a limited number of times unless he gets more materials. He made sure to not get seen by cameras or the guards in the novel, though he was also wearing a hoddie if I remember right to help hide his face when he wasn't using his stealth skill after he left, and his alibi was solid since he was still in Japan and no one knows of his shadow travel skill aside from the S rank female hunter, possibly Jin ho, and possibly the chairman of the hunters association. However
his big mistake was that Jin he's sister seen him and while she didn't recognize him at first she knew she had seen him before so later on when Jin Ho's father had given up on the idea of it being MC his daughter ended up seeing a picture of him with Jin ho if I remember right and told her father seen him leaving the hospital the night he was cured