If you asked Angel which kind of energy aura is the easiest to distinguish, his answer, without a doubt, would be: Mysterious Aura.
The feeling that Mysterious Aura gives is absolutely unique—filled with the unknown and impossible to pry into—and it is also the energy aura with the strongest "sense of presence"!
This "sense of presence" can be understood as a kind of boundless transmissibility.
If it is not deliberately concealed, even separated by hundreds of miles one can easily perceive Mysterious Aura.
And from the side door of the row house that had just been opened, the energy aura spilling out was precisely… Mysterious Aura!
This Mysterious Aura was very faint, clearly suppressed; but its "sense of presence" was too sharp. Even diluted countless times, Angel still captured that exceedingly uncanny aura at the very first instant.
"There's a Mysterious Object inside?" Not only Angel could feel it, the others present could as well, and they all turned their heads to look.
