What I did is use Cloud with
4x cut (works well against single or small group)
the master materia (fun to have)
enemy skill (great stuff if you have all enemy skills)
odin (gotta love the chance of instant death, and because a lot of them are weak enemies, you have a decent chance up until the last couple battles)
ribbon
mystile
ultima weapon

with that, I didn't have much of a problem getting omnislash and w-summon.