While Arad struggled to consume Betty's abundant light, Jack attempted to suppress Lydia's unyielding radiance. She stood at the heart of the open field, leaning on her longsword with pure divine light seeping out of her body like a beacon of hope, holiness, and unfiltered godly arrogance.
Jack held his wakazashi in one hand, took a deep breath, and stabbed the ground gracefully.
[Eclipse]
Darkness rushed out of the wakazashi's blade and flew toward Lydia, drowning her in a massive half-sphere of pure, onyx shadows.
Jack noted several things about his [Eclipse].
First, [Eclipse] is a power of the wakazashi, not himself. Thus, it's unbound by his physical condition. That allowed it to keep working even when he was asleep or unconscious, but also limited how long it could be used and how frequently.