Act as a fantasy concept artist with 10+ years of experience in creating mythical characters. Design a stunning midjourney portrait of a fierce mermaid warrior wielding a sword crafted from luminous pearls. The setting should be an [underwater coral palace] with bioluminescent flora, where the mermaid's [iridescent scales] shimmer in the ambient light. Emphasize her [regal yet battle-worn expression], conveying both elegance and strength. Include intricate details like flowing seaweed-like hair, armor made from seashells, and the pearl sword glowing with an ethereal aura. Use a color palette of deep blues, teals, and pearlescent whites to enhance the mystical atmosphere. The composition should be dynamic, as if she’s emerging from the depths, ready for battle.