One had to know that the Devil's Den formation was still functioning normally, hindering one's Spirit Sense.
However, a Sword Intent wasn't something that could be completely isolated by Aksai's formation. Recognized as the bane of formations, a potent enough Sword Intent could shatter thousand formations in a single strike.
Of course, the Sword Intent released by Aksai borrowing Kalina's Bright Scarlet Blaze didn't have such power. In fact, even a true sword cultivator like Varesh was far from achieving such a profound realm in his sword cultivation.
However, since Aksai's Devil's Den lacked the means to employ many Intent-based techniques including Intent Isolation technique, it could not prevent a Sword Intent from resonating outside the formation.
Furthermore, Varesh was no ordinary late-stage Lord. He was a true sword cultivator with a genuine sword cultivation technique.
