The plan to bring down Sanguis Pluvia could not be simple. It was clear that they were working with the Fuegan to fight the Henali, and could possibly even be a part of the Fuegan themselves. The reasons behind their attacks against the Origin realm were unknown, but it was a fact that they had managed to hide from the Henali.
Lex did not, for a moment, think that he was stronger or even smarter than a Dao Lord - any Dao Lord. The only advantage he had working for him, according to the research he had done, was that Sanguis Pluvia were focused solely on hiding from Dao Lords, and did not consider anyone else a threat at all.
That made sense, in a way. If they could even hide from Dao Lords, then how could those weaker than Dao Lords ever possibly find them?