Taking on Satan with wands looks like it'd be difficult. From what I saw on the wiki, there's literally only two Holy skills: Bright Homing and Ougi God-Sealing Circle. Since Bright Homing requires you to stand still for a while as you chain off the hits, that seems like a bad skill to use against Satan. I guess the best bet would be to brute force with a neutral element. I've never even seen GSC so I know nothing about its damage, run up or cooldown.
I don't think *I'll* have much trouble fighting him, when I get that far anyway. My main has access to Exorcist Arrow, Amaya's Punishment and Sunlight Strike. My secondary has the same plus Holy Pillar. My sword user has Holy Empty Sky Slash (I think Sacred Strike might be Holy as well). My bow user has Exorcust and Amaya, my staff user has Holy Pillar, my spear user... might be boned, my Odachi loli has Shining Enma Slash (plus access to HESS and Sacred Strike), and my Gandalf-wannabe has HESS, Sacred Strike and Holy Pillar. So it's just my Lancer I need to worry about, but I think he can brute force.