Leonel didn't have time to think about why it was that these two demons managed to find him. However, he realized one thing instantly: they had been stalking him.
Before Leonel made the choice to target anyone, he first checked in on where everyone was. If they were too close to one another, he wouldn't even take the risk of attacking.
All of the spells he had written could be walked directly through, there were no physical obstructions. As a result, crossing over from one region to another was not only easy, but seamless. This was how Leonel managed to maintain the illusion that his enemies were always alone. If there were physical obstructions, it would become too obvious, too quickly that he was interfering with their senses. Once that happened, everything would be exposed.