We all know the correct opening which includes DP, since the lovely topic out there.

However! What is DRK supposed to do with DP after the opening, during the boss fight?
I was trying my strength on Burden of the Son Dummy trial and this is what i found out by myself:

Using DP without Blood Weapon extends the availability gap between DA+SE usage by one delirium rotation + significally lowers mana pool; if you like to ride on constant 20% max mana value it is a bit harder to use both DP and DA+CnS if CnS is going to be available soon at the same time.

DP is 150 potency. DA + SE - DL is 120 potency.
Numbers are saying it is a good deal, but i tried to make this trial in two ways:
1. Using DP asap when only mana allowed me. Trial has ended at 3%
2. Ignoring DP completely except opening. Trail has ended at 4%.

It might have been RNG, but i hope it weren't.

Weaving DP into rotation during boss fights after opening:
Board the train or leave on station?