both ruby and emerald weapon are possible to beat if u have to good materia combine with the good one. (a winner materia : phoenix+final attack). And if u want to beat ruby easily, just kill 2 of ur character before the fight, then, he wont suck ur character from the battle.
ps : a master...
Ya, the moving wall is quite dificult, but if u have bahamut and leviathan, it should not be so hard. And the hardest part of the game is when u only have to beat up ruby/emerald weapons. And i've finish this game at least 7 time.
Esf is a 100% multiplayer game, so you will be unable to play single player. After, maybe this message show up because you dont have HL v.184.108.40.206 . Downlaod and install the update and it should be fine.