Winspear
Winspear/Noisemother
Oh, I assumed it was standard octave48 for C# from a 9 string? O_O
Perhaps something like this then?
len 27.7
c1# .105 danw == 17.21#
a1 .064 danw == 18.03#
e2 .046 danw == 20.63#
a2 .032 danw == 18.61#
d3 .024 danw == 18.61#
g3b .018 danw == 16.91#
Assuming you then meant the 10-52 in E standard on 25.5, but I wouldn't suggest trying to go that tight on the bottom of a 27.7 in C# as it would need something like a 120 which is just going to be super muddy. So I've gone with a more typical 'middle heavy' set here that tapers off the tension more like a 46 E than 52 at the bottom for some brightness.
The Ernie Ball 9 string set skipping the 80 is a nice solution for you that gets you extremely close to this suggestion but with a 16 plain on top (which is a good alternative to an 18 wound, if you aren't opposed to having a single plain string on the guitar which I never enjoyed). I'd grab that for ease and tweak from there to taste.