A mystical mermaid warrior emerges from the depths of a radiant, glowing ocean. Donning bioluminescent knight's armor, her scales shimmer with iridescent hues, as if reflecting the swirling colors of the underwater world. Her tail, adorned with intricate synthwave metal accents, glimmers like polished obsidian. The surrounding water is bathed in retro neon light, casting an ethereal glow on the warrior's determined expression. With navel-high waves crashing against her legs, the undine's beauty and strength are showcased in this highly detailed, photorealistic digital painting.,mermaid,undine