Eight figures, six sets of footsteps.
No matter how hard Hao Xuan tried to listen there simply was no noise to be heard. He couldn't see their feet without making any conspicuous movements but judging from the figures swaying backs, or lack thereof, it was pretty obvious their feet were not touching the ground.
The first figure was just behind the first guard while the second was right in front of Ma Jiang. None of them had noticed their presence either since they were all extremely calm.
As for the shape of the two figures, all that Hao Xuan could see were shadowy humanoid silhouettes without any definite shapes. It LOOKED like they had two arms and two legs with one head and torso but the darkness congealing and then dissolving on its own every second, it was really hard to tell.
It didn't look like they meant them any harm since they simply followed them in silence.