Originally Posted by
Siriel
I'm not sure how the craft essences work so I can't answer there, sorry.
Even without Brave Buster Chain, Lu Bu should deal good damage since he bypasses the Ruler Class Damage Reduction. And if you can build up his NP (he starts at 80% thanks to Kaleidoscope, so it's not too hard) then God Force will take a good chunk out of her health bar (especially if you use the Master attack buff and Lu Bu's own during that turn).
Just be sure to use damage prevention like the master skill or Shielder's second skill, because as a Berserker he takes a lot of damage and dies fast.
In the worst case where you get wiped, if you have all three of your Command Spells consider using those to revive your team will full HP and NP bars. You won't need any help for a while after Ruler Alter because the difficulty of the following story quests is far lower.