Originally Posted by
Shurrikhan
TBN has nothing to do with the degradation of MP management.
What you're doing is like blaming Shinten/Kyuten for the loss of unique costs on Guren/Senei and the pruning of Kaiten and Seigan and if Yaten/Gyoten lost their Kenki costs and damage. They're not the cause; they're the sole survivors.
Likewise, Dark Arts, MP costs on other skills, etc., all existed simultaneously with TBN. The same period in which we got TBN also gave us the most involve MP manipulations and thematic means of sustain that we've ever had, and to which TBN was synergetic, not mutually exclusive.
TBN didn't remove Darkside, Dark Arts, Dark Passenger, or spammable Abyssal Drain. It's simply the sole survivor of intentional simplifications.
Costing MP is, however, the reason TBN can be as flexible as it is, allowing 50% barrier HP (2 casts at 25% each) compressed into as little as 9 seconds. Meanwhile, embedding Oblation into it would both waste its scaling value on non-tanks targets and make TBN itself less flexible.