Yes and no. Damage wise it will be stronger, and even more so if you use mysterious + GS S5 + wise skill unit ssa. You will lose the every so often 2nd PP bar though. The Rod S5 does work for phantom as well... the atk speed increase.
However, there are significantly better Liberate weapons like DB, katana, sword, wand, bow, JB, knux, and partisan. (DB, kat, wand all work with their successor classes too.)
And if anyone is interested in more detail about each S5,
https://ranger0.com/20191221/11725.html#toc_id_13 .