No, just do expert, but settle on just farming one thing. In case of the upcoming event, a good option would be the water SSR weapon (and if you got some time afterwards could grab a dark/water assault SR) or one of the eidolons. The eidolons are rather bad though, so would just be a temporary stat push for you. So in the end: weapon will help you longterm, eidolon short term, whichever you choose is up to you. Dark SSR is a defender, so unless dark's by far your strongest team, go with the water one.