Wise Necromancer Yuura

100% boost to Atk, 40% boost to max HP, enormously boosts BB Atk, slight HP absorption & damage taken hugely boosts BB gauge

Hugely boosts Atk when BB gauge is full & 50% boost to Spark damage

BB

Nefarious Revenant

1 DC25

17 combo powerful Dark attack on all foes (partial HP absorption), fills own BB gauge to max, hugely boosts BB Atk for 3 turns, Spark damage boosts BB gauge for 3 turns & damage taken considerably boosts BB gauge for 3 turns

SBB

Soul Bind: La Evils

2 DC27

12 combo powerful Dark attack on single foe (partial HP absorption), 10 combo Dark attack (consecutive uses boost damage), powerful additional attack on all foes for 3 turns, fills own BB gauge to max, hugely boosts BB Atk for 3 turns & damage taken considerably boosts BB gauge for 3 turns

UBB

Nightmare Deplete

2 DC30

15 combo massive Dark attack on single foe (partial HP absorption), 12 combo massive Dark attack, massive additional attack on all foes for 3 turns, enormously boosts BB Atk for 3 turns, enormously boosts critical damage for 3 turns & damage taken enormously boosts BB gauge for 3 turns