Ruby Sanctum is a raid instance in the game World of Warcraft, introduced in the Wrath of the Lich King expansion. It is located in the Crusaders' Coliseum and serves as a final challenge for players seeking to defeat powerful bosses. The raid features several encounters, including the formidable Halion, who is the main antagonist. The setting of Ruby Sanctum is a beautiful, yet dangerous, area filled with vibrant colors and intricate designs. Players must work together to overcome various mechanics and strategies to succeed in defeating the bosses. The raid offers valuable loot and achievements for those who conquer its challenges.