Developed and released the Battle for Treasure Island clash scenario for the qwrtln/Homm3BG-mission-book repository, expanding multiplayer content with a new, repeatable game mode. The work involved designing detailed map layouts, creating new SVG graphical assets, and authoring a comprehensive LaTeX document that outlines rules, setup, and victory conditions for two to six players. The scenario integrates defined map tile arrangements, starting resources, unit allocations, and timed events to support balanced gameplay. All changes were tracked through a dedicated commit, ensuring traceability and maintainability. This feature-focused contribution emphasized content development, scenario creation, and robust documentation for future expansions.