can you explain the actual problem in more detail ?
do you think hashcat (or your devices) are not working at all or is the problem "just" that you think you are testing the wrong password candidates (or wrong character set + mask etc).
From your output it's not clear if hashcat finished or what is going on.
how did you generate demo-hash.txt ?
Did you try to see if everything is working with your specific setup (hardware, hashcat version, operating system etc) when trying to crack an example hash with known/easy password ?
Please explain in more detail, because it's not clear to me if you are just confused about how charsets are defined (e.g. see .hcchr file, this has nothing to do with "rules" and also not directly to do with hcmask files, it's a charset file or defined directly in the command line as your example above) or if you have some more serious problems with your setup/hardware/installation.
do you think hashcat (or your devices) are not working at all or is the problem "just" that you think you are testing the wrong password candidates (or wrong character set + mask etc).
From your output it's not clear if hashcat finished or what is going on.
how did you generate demo-hash.txt ?
Did you try to see if everything is working with your specific setup (hardware, hashcat version, operating system etc) when trying to crack an example hash with known/easy password ?
Please explain in more detail, because it's not clear to me if you are just confused about how charsets are defined (e.g. see .hcchr file, this has nothing to do with "rules" and also not directly to do with hcmask files, it's a charset file or defined directly in the command line as your example above) or if you have some more serious problems with your setup/hardware/installation.