According to the CIS-2017 regulations.

Who will choose him and how? What if no one wants to be a judge?

Random selection among the viewers. Only for hardcore players.
I would strongly support Kostya Knysh as a Judge.

But seriously - we will find a solution. Over the past years, the judge's role has mainly involved providing updates on the current game situation on the forum, rather than maintaining game discipline.
The only problem is that in the mornings, I have to search for everyone and wake them up - but this year, it's time to stop chasing after the "Sladyshi"...