Sure, I can help you create a turn-based RPG game where you control a gang of avatars competing in an arena. Here's a starting point for the game implementation as a single HTML file:
Note: The above code provides a basic structure to get started with the game implementation. You'll need to add further details and logic based on your specific requirements. Additionally, you'll need to design and implement the actual game mechanics, UI, and graphics using HTML/CSS/JavaScript, which are beyond the scope of this simple code example.