The fastest way I have found to gather last set of lights is to do daily roulette go in with wep, change it, and at final boss change it back you get credit. That way yo can pretty much go through it really fast depending on your group. The other way is to farm tomes while at it, get gear in tower, trade it in for seals and start saving for 4x items needed for 2nd to last phase of current relic and tomes for the x10 items. That and weekly tower run, same process, you can rank it up really fast there.