For most of this arc, Natsu’s been his usual feisty self. We’ve seen him mad, we’ve seen him determined, we’ve seen him brought down and get back up again, we’ve seen him as rescuer and captive and rescuer again, we’ve seen him nearly get his soul absorbed and be separated from his partner.
But through all that, I feel like he’s maintained a high level of energy and resilience. He even took time out of his fight with Tempesta to get into a scuffle with Gajeel and make silly bets.
I thought that might be his last light-hearted moment for a while.
Then Torafusa unleashed his poisoned water, and Natsu succumbed to it:
It’s rare—and hard—to see Natsu helpless and passed out like that. Gajeel was shocked by it. And when Gajeel defeated Torafusa, Natsu and the other girls just ended up flopped on the ground. Ouch.
When we see him for the first time this chapter, Natsu is conscious, but quiet. Just look at his body language in the right panel. The others are close together, and earlier were facing each other, and talking. Natsu’s sitting well away from the group and he’s got his back turned.
(And the Nalu shipper in me would like to point out that Lucy was the first to notice his posture and ask him what was wrong. She was sitting facing Gajeel and the other girls, but she turned sideways so she could better see Natsu as well as the other group.)
Yes, Natsu is super-competitive, but he tends to be vocal and in-your-face about it. When he’s got his head bowed or back turned like that, it’s because he’s preoccupied with something more serious.
Natsu heard Acnologia before Gajeel did. It’s probable that Natsu had been feeling uneasy for a while, before he pinpointed the cause. And when he realized who was coming, he actually trembled.
We went from a fired-up Natsu to a passed-out Natsu and now we have a very shaken Natsu:
And Igneel’s about to join the fray.
Watch out, Natsu! I see Angst and I think it’s coming your way!