Personal opinion, but you're better off doing RoCT than farming them via Ep1 Ultimate difficulty Canune or Episode 2 Ultimate difficulty Crimson assassin (Purplenum ID on both cases), and you also get a chance at getting a Yasminkov 9000M from Olga Flow with Oran ID.
[The thing about farming yasminkov 9000M Is that Canunes are one of the most scarse monsters of the game; and as for Crimson Assassin, despite It has a good spawn on a certain quest of episode 2 (AKA Battle of Beaufort) [AKA tyvm @bobshlibidich ] {or maybe Max Attack U Temple with an average spawn of them, too, I guess :v}, you have to know that the chances of getting hit% on a weapon Is like 1% [unless your ID Is yellowboze, with a chance of 3%] unlike on episode 1 & 4, which Is 5% for all IDs (sum1 correct me If I'm wrong >.<), and there's also the Issue about value % on episode 2, which Is hardly ever as good as episode 1 & 4's, I hardly ever get to see % on any attributes (and hit%) going for above 30%