The Beast Goblin King was impressed by Adam's ability and surprised by Adam's killing intent and powerful aura, so it no longer regarded him as merely an easy opponent.
One's aura wasn't only a representation of one's power, but was also formed by one's willpower, determination, drive and self-confidence, which were all key qualities for a cultivator as without them, one wouldn't have the right mental state to succeed as a cultivator and surpass their limits.
Adam was too focused on forming his skill and wasn't completely focused on the powerful beast before him that he had to kill, but he wanted to get the battle over with and had become more accustomed to the use of the Burst Movement Skill that he had formulated.
"You might be faster than me, but we will see who will come out on top," said Adam before bursting off his feet using the Burst Movement Skill, but still staying close to the ground.