When Lucas had stepped foot in Valeria with Belle, he felt the eyes and presence of someone who had been tailing them for a while. Of course, he never turned around and went to find who it was. From what he had heard from Edith, that the Grim reapers and hellhounds who had been unleashed into the land of the living to find anything and everything that was a free soul without a body including the fallen Grims, he had been careful.
There had been times where death reapers themselves had turned to mortals, walking amongst the people in this land until they were caught and sent back to the land of the dead for punishment.