1girl, arknights, black_one-piece_swimsuit, casual_one-piece_swimsuit, high_ponytail, holding, holding_staff, infection_monitor_(arknights), long_hair, looking_at_viewer, lucy_(rusi-juren328), lying, official_alternate_costume, on_back, one-piece_swimsuit, parted_lips, partially_submerged, pointy_ears, red_eyes, shining_(arknights), shining_(silent_night)_(arknights), solo, staff, swimsuit, thighs, very_long_hair, water, white_hair