Bold Fighter or Vengeful Fighter?

It really depends on his weapon. If you’re going for Berkut’s Lance then go for Vengeful Fighter, if you’re going with Slaying/Firesweep Lance then Bold Fighter will be better.

Steady Breath's effect won't stack with Vengeful Fighter, so it's somewhat moot having them together. To get around this, simply give him Bold Fighter and QR seal for dual phase functionality.