In the popular online action RPG game Hero Wars, the player has to solve some simple but fun puzzles to win loot such as weapons and cash – assuming the incessant ads I’ve seen on Facebook are all legit. The left image shows 4 purple question marks embedded in a grid (a5/d4/e4/d1 in algebraic chess notation) with each question mark corresponding to a different action: (i) pull horizontal pin, (ii) pull diagonal pin (iii) pull vertical pin (iv) switch the hero with the wine cask. To make the puzzle more challenging you also have to solve the Sudoku shown on the right.
One of the cells is missing an even digit. Which cell and why?
Solve the Sudoku. If there are multiple solutions then you have to choose wisely!
Next, superimpose the completed Sudoku onto the left image so that the four purple question marks contain 1-2-3-9 in some order. You can rotate and reflect the Sudoku if necessary. Taking the Fourier Transform is not allowed.
The digits 1-2-3 mean “perform these steps in order” and 9 means DO NOT TOUCH. If you have the correct permutation then the loot is yours!