Originally Posted by
Zairava
Also, to continue, I did go back and rewatch the trailer for DRK repeatedly to see if I could find anything more, to which...not really.
However, I did notice that it's roughly 18 seconds from Delirium's activation to where they used Unleash, so it's very possible that the mp restore timer just wore off.
My guess is that since Blood Weapon is the ability actually evolving, that Delirium keeps the 5 stack system from Blood Weapon. If it were Delirium -> Blood Weapon I'd find missing out on 1.2k mp more likely.