I currently know there is 3 signs in Zee Bawx.
There is one ontop of the mountain,One in the swamp next to the giant tree to your right,And one in Grimdark top right corner behind pillar.
Each Cross has a unique message left by Ashe when she first found her mask.
After you actived all 3 crosses all shards are super powered now it add's 16 to each shard you find.
Avoid Trap shards they take away extra.
Since I don't know how to upload I don't have any photo's or video's for viewing.