Adamant Ancient Svalinn

100% boost to Atk, Def and max HP, considerably boosts Def relative to how low remaining HP is, considerably boosts Atk and Def for 3 turns when guarding, 15% damage reduction & negates critical and elemental damage for all allies

5% damage reduction for all allies when Damage Reducing Sphere is equipped, boosts Atk, Def for 3 turns when guarding & hugely boosts critical damage for 2 turns when damage taken exceeds certain amount

BB

Flamma Illuminaris

1 DC35

22 combo powerful Fire attack on all foes (with enormously boosted critical hit rate), 50% damage reduction for 2 turns, hugely boosts Atk, Def for 3 turns, hugely boosts own Atk, Def for 3 turns, considerably boosts own max HP & fills own BB gauge to max

SBB

Stella Incaeseus

1 DC300

25 combo massive Fire attack on all foes (with enormously boosted critical hit rate), 20% damage reduction from all element types for 1 turn, hugely boosts Def relative to Atk for 2 turns, hugely boosts Atk relative to Def for 2 turns, negates critical and elemental damage for 2 turns & activates Fire barrier

UBB

Exitus Ultima

1 DC40

10 combo massive Fire attack on all foes (with enormously boosted critical hit rate and additional 5% damage of foes' max HP), 100% damage reduction for 3 turns, enormously boosts Atk, Def for 3 turns, enormously boosts Def relative to Atk for 3 turns & enormously boosts Atk relative to Def for 3 turns