i fought Ruby 1 on 1 with Cloud! (and won

) a most horrible adversary, but kinda cute when you throw one of those smoke grenades (that allow you escape from battle), you'll see Ruby standing up on the quicksand looking menacingly at the highwind
fought Emerald with Final-attack+Revive, and a couple of counter-attack materia and knights of the round+ mime... to me, it seems he does less damage if you equip less materia on your characters