Fastest series grind?

[Arkdra]

Crystaline Conflict or Frontline?

Crystalline Conflict. On average you can do 3 cc's per 1 frontlines. 3 cc losses is 2100 series exp versus 1500 for a frontlines win. That said, doing the frontlines daily is worth the time since they about doubled the series experience for it.

Edit: I personally do a daily frontline match and do a daily cc. Works out to a decent blend of not taking forever in real time while also not taking up a lot of in-game time.