This hole section just makes the Mc such a heartless jerk. He could of at least talked to his buddy about saving the father. Even if he saves him now he inflicted this pain on his only friend. He did that by not already saving the dad. He is just so self centered is crazy
There are many numbers being thrown around in regards to how many elixirs he has left. He has 5 left, the crafting creating 6. Also, he still has Demon King Blood and World Tree Fragment, but needs more Spring Water if he wants to create more elixirs. So, he doesn't just have 1 or 2 elixirs left like some are saying
Source: ch 108
He only got 2 drops/use left of the water of life. He can't carelessly use it even to his friend's father. Besides it can help cure the hunter association chairman. What if word got out that he can cure that disease? People will flock to him and beg to cure their disease.
I think everyone is forgetting that jin-woo is being very careful with his stuff. Originally he didn't know if the father was going to try and sell it and bolster his company. He is more than likely going to use it eventually but it takes time to trust others.
Of course he's going to help, especially after seeing Jin-Ho like that. Imagine the chaos that would occur if people knew he was able to heal people from this disease?
TertiaryOcelot