Deciding on how to approach the demon beasts without being noticed before he could attack, he didn't immediately jump forward to deal with the demon beasts. Instead, he first attempted to see if he could get some help from the formation spirit before he made his move. After all, everything he was doing was essentially for the purpose of helping the formation spirit while at the same time using the opportunity to complete the side quest.
Maybe not that surprisingly, he did get an answer from the formation spirit upon requesting assistance, though it was clear that the formation spirit couldn't do much more than help him provide a distraction when he made a move. Buying him a bit more time to properly assess the overall strength of the twenty demon beasts that he needed to take down.
To be honest, he didn't expect any help from the formation spirit given how it had seemingly vanished after asking him for help, so the little assistance it planned to provide was more than welcome.
