I'll try this later but I think this is not the problem. I tried a bunch of different things to install hearthstone. In one of them I used wget on the script's link. It downloaded fine.
Also, the installer window does appear. If the link was broken, I think it would not even download.
Maybe the installer from the link is, somehow, corrupted.
I was using Manjaro-Gnome. Now I'm going to install Manjaro-XFCE and see if I can install it there. The reason I'm doing this is because I discovered that the catalyst driver from AMD has a certain incompatibility/bug using the new version of Gnome. So I'm going to try this new path. Even though I do not think that this is the problem, maybe it'll work.
Just so you know, it didn't work.
Even with XFCE fresh installed and using the catalyst drivers. This is pretty sad.
If you have an idea of what I could do, please tell me.
Thanks for the help, anyways.