Fairy Tail (2009)

S5E43 Believe

In a thrilling conclusion to the arc, Natsu and Happy find themselves at the heart of the Celestial Spirit Beast, where they encounter the original Celestial Spirit King, bound and facing certain doom. Meanwhile, the rest of the Fairy Tail guild battles fiercely from the outside, attempting to defeat the beast, which continues to grow in power with each passing moment. Despite their relentless efforts, they struggle to make a dent in its defenses.