"Singing Viy Challenge!! Pano Mang Huthot ng Delata (Reaction Video sa Aming Annivlogsary)" likely features a fun challenge where the participants sing while reacting to memorable moments from their anniversary vlogs. The "huthot ng delata" aspect adds a humorous twist, suggesting funny or exaggerated performances. Expect lots of laughter, nostalgic moments, and entertaining interactions as they celebrate their anniversary!