Luminous' Sanctuary (Tensura Vol 23)

This battlefield had been transformed into a Sanctuary, maximizing all magic effects. Even Luminous couldn't do this without a cost. But without it, defeat was certain… Unbeknownst to all, Luminous continued to support the heroes, hiding pain so great the term "self-sacrifice" seemed trivial.

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While the enemy's strength was suppressed to less than a tenth within the Sanctuary, that advantage would vanish if they escaped outside