Use a Cheat Engine. Open up your game, then minimize it and open Cheat Engine.  Load up your game’s exe file and let it scan the game. Now, enter the current number of souls you have and select ‘First Scan’. After that is done, enter your game, spend some souls, and then come back and select ‘Next Scan’. This will give you the address that governs your soul count. Drag it into the drop-down below and now you can freely manipulate your soul count. Careful – this might result in a permanent ban.