I just thought of another way to improve the walker by evading an sqm when there's an invisible monster. How would it work? If the bot tries to move onto an sqm that seems to be walkable and fails for several times, the pathfinder blacklists the path and returns it as walkable after a few seconds. In my opinion this might lower the detection ratio (in theory). Sometimes the character gets surrounded with a few visible monsters and just 1 invisible monster and it still thinks it's not trapped. This also leads 'only if trapped' function to not work properly and makes the bot step on the path that's not walkable constantly until the monster reveals itself instead of just killing one of the visible monsters and continuing the walk. This is really annoying and looks so bot-like.