At the moment (6.58) Dark Knight restores 50 blood and 3000 mp over 5 hits upon using Blood Weapon but as shown in the 7.0 media tour it only restores 30 blood and 1800 mp over 3 hits.

The -20 blood isn't particularly impactful due to Living Shadow no longer requiring 50 blood but the -1200 mp negatively impacts Dark Knight's ability to cleanly perform 4 Edge of Shadows every minute (8 every 2 minutes) due to now generating less than 12000~ mp/minute.

Adjusting the new Blood Weapon/Delirium button by +400 mp/hit would likely resolve this issue entirely.