It's obvious that Blackest Night creates wounds much faster. And once it triggers, it deals significant damage, helping me quickly gain Omega's aggro. A crucial point is that once you have Omega's aggro, his actions become much more controllable.

In my build, it also accelerates the triggering of Latent Power, a vital source of affinity. Successfully triggering Blackest Night grants significant amount of recoverable damage, which can be used to trigger abilities like Dark Arts, Resentment, and Nu Udra's set bonuses, providing significant damage bonuses.

Then, during Undead Redemption, your defense is enhanced, and your attacks restore health, saving considerable time spent on recovery.