looking at the walkthrough,cant help but feel like there is a logical jump:
ertneqvat gur cbfvgvba bs obbx sbe cneg bar,rry naq zrqny znxr vg fb vgf abg va ebj gjb ohg v qbag frr jul vg pbhyqag or ng ebj guerr,abguvat ohg gelvat gb svther bhg jung jbeq pbhyq or va ebj guerr jbhyq cerirag vg sebz univat svir abgrf
edit:nqzvggrqyl vs lbh gel gb chg obbx va nal bs gur guerr fcnprf bs ebj guerr vg jvyy rvgure yrnir ab fcnpr sbe sver be znxr ab jbeq ohg guvf jbhyq fgvyy erdhver guvf fgrc gb or nsgre svthevat gur ebhtu cbfvgvba bs gur sver
nevermind,i see now the rule about the empty spaces that would make sense indeed