Logan observed the situation and noticed a significant crack in the barrier array, one so fragile that a light touch would immediately create a large gap.
His guess was that this array was the City-protecting Array of the city walls, which, if anything went wrong, would put the entire city in imminent danger.
No wonder they offered a high price of one million Top-Grade Spirit Stones. As for repairing the array, Logan was more than familiar with it, hence the confidence with just a glance.
Of course, he didn't blindly nominate himself, knowing that this was the Outer Domain where the slightest carelessness could lead to disaster, and the situation was certainly more complicated than he imagined. This crack in the barrier was not naturally occurring; it was clearly the result of sabotage, possibly hinting at a conspiracy brewing in the shadows.