When Han Fei entered the teleportation array, he didn't find any danger.
This was an ultra-long-distance teleportation array. Although Han Fei didn't know the destination, he could reverse time in the teleportation array at any time, even forcibly break the array and get out.
A moment later, what Han Fei was worried about happened. There was a problem with the teleportation array. This was He Daoyuan's scheme, which was to let him jump into his trap.
However, this was actually Han Fei's plan. As long as He Daoyuan was lured away, he would never be able to return.
This meant that the moment he entered the teleportation array, this expedition had already succeeded.
Now, as Han Fei said, this was the final battle. Either he died or He Daoyuan died. Han Fei believed that it was impossible for him to die, so He Daoyuan must die.
At this moment, the latter half of the teleportation array was enveloped by a deathly aura.