I only have 2 copies of Ra or I’d use that. Reducing the difficulty to Warlord2 decreases the time by about 5-9 seconds, and anything lower and my TDS will wipe out before collecting enough souls so I think the team I have is unfortunately the fastest.
After doing some math, with where I’m at and the average it takes me to complete a battle, I should have DB crafted in 20 hours of play time.