There are lots of ways to kill satan[ok not much that are 100% effective but there are].
Tank with Champ, Pala or Lk or HP[lk or champ are the best, hp is just a last and bad resource that sometimes works with heavy reduces to demon lol, pala is more because of the auto-guard think even if there are better use of that class but works], devo it, make sure tank has fcp or at least shield protection thing and just make sure the devo doesn't die and the pala is always alive being it by heals or pitch.
Nuke with asura or ad or spiral pierce or even ds snipers[any of this works but if using spiral is better that the lk is also the tanker lol].
Someone double 2 sl and use the auto-res on everybody for the anti-res phase[at least this buff but you can[and should] use the -1 hit too to make sure everybody survives the eq phase] if party can't survive the eq.
Medusas/ED for the stone aoe phase.
Other stuff is the basic. If you can do Berz easy, you can do Satan easy too.
Just be careful to never hit the slaves or the skills will pwn everybody.
Don't forget to read the skills of satan to know what to do at each step of his % of hp since he uses a set of skills that are kinda nasty.
Example for satan:
http://www.youtube.com/watch?v=tcD1bQ6RojY
