^What Hanzo said

The only caveat I'd say to that is to always do Trial Breakthrough if you have the time and/or you have the characters to challenge it. It still gives you Cultivations Runes and starting lvl 70 and up (and probably before then), runes become harder and harder to keep up for your teams.

It doesn't help that you're always getting new and better characters that replace your team. (All those cultivations runes used on Neji and now we have GNW Neji...)