His last attack took a lot of Spirit Power from him. In the end, he used around 25% of the total of his Spirit Power, wasting most of it to burn Jack-o'-lantern to nothingness.
Considering his reserve was as big as Amber and Ibaraki Douji, 25% of his Spirit Power was actually a totally ridiculous amount, comparable to many normal Slayers.
'The fastest way is to replenish mine with Amber or Ibaraki, but… I can't do that right now, right?'
The other way was to meditate. And when he did that, his body would be vulnerable to attack. Going back right now was something he didn't want to do, and he wanted to find Boogeymen as fast as he could.
And there was also the matter of the driver acting strange and the Jack-o'-lantern asking for help from someone he didn't know. Maybe Jack-o'-lantern's attack was something planned by someone else who wanted to stop him from searching for the Boogeymen.
