I agree for an MC, Natsu is one of the worst his level is inconsistent and inexplicable and his personality is annoying in the long run. The only arc where he is tolerable is Tartaros but Alvarez made me hate his character (This arc is only for Natsu it's always Natsu Natsu is the strongest only Natsu can do it honestly the arc should have been call Natsu+Erza VS Alvarez the others were treated as volunteers)
I’ve found Natsu less appealing the more he’s treated as “the chosen one” or as he’s got more and more special main character treatment. I never found it too bad prior to the Grand Magic Games arc, he was certainly a key player and was often the one who did take out the top enemy of each arc, but it was usually with some help/ support from his friends which I thought was how this series should be. when he did have a unique role to play it was balanced and left room for the others to actually do their bit too.
His win against Sting and Rogue was probably the first moment I really hated, even if it was meant to be a gag, ultimately that began to unbalance his role in the story. Then Tartarus made it much better again, his fight against Mard with Sting and Rogue, then Gray has to be one of the best in the series. That’s the sort of battle I’ve enjoyed seeing from this series! But after that we went into full on one punch guy mode, I thought Ikusatsunagi would have been an ideal call back to the lullaby fight right at the start of the series, maybe this time Lucy could even have joined in to show off her new star dress powers? But nope. Let‘s just single out Natsu’s power gain instead.
Exactly how strong he was in the Avatar and Alvarez arcs was so vague as well, was he boosted due to Igneel’s power in that time? Was what he was doing at that time just normal for him now? Did we actually see a glimpse of what would have been his power as END if that plot hadn’t been mostly dropped? It didn’t help that the Spriggans used “cheating magic” (Mashima’s own words) so a lot of battling them came down to luck. He was vulnerable to Brandish, but Dimaria’s time powers didn’t affect him?
Into the 100YQ I thought he might get a soft reset, I can forgive that he’s doing most of the heavy lifting against the dragon gods, he‘s got a type advantage after all, but they’ve been pretty boring so far. The side plots like Gold Owl and the white witch are the more interesting bits of this story, I hope he doesn’t start tearing through what could be some decent fights coming up… that’s the problem, you just can’t tell if he’s going to any more.
Despite this I think Natsu has been/ still is one of the characters that’s kept me following the series so long. I just wish we could go back to him having a more balanced role in the story. Sneezing and destroying cities, and being able to zero diff enemies his friends would have to battle seriously ruins his place in the story. The fact it’s selective/ inconsistent just makes it even more grating.