Min/Max Boards

In-universe, humans use what is called Divine Magic, performed by infusing the air with magical energy (as opposed to the monstrous Vandels, who use 'Dark Magic' performed through channeling energy through the earth). Burst End is the highest-level divine fire spell in-universe, accidentally learned by the secondary protagonist character Poala.

Burst End works by taking a large amount of fire magic and compressing it within one's hands until it's pressed to its very limit. Once it's in that state, it's simply a matter of forcing that mass of divine fire forward, creating a giant cone-shaped area of fiery destruction. The explosive force is powerful enough to blow people away (as demonstrated with Beet, who was literally blown skyward when he was falling near the spell's strike range [he wasn't even in the area of the fire, and still got launched upward]). It is noted by Kissu, the in-universe Divine Magic genius, that the spell is powerful but risky, as a loss of focus while compressing it could result in the spell's force being turned upon the caster as well.

Poala accidentally learned the spell while trying to perform a fire spell against a Vandel who caught the spell while it was still in Poala's hands and compressed it to keep the fire from striking his body. Poala continued pumping power into the fire, attempting to overpower the Vandel's hold, until she eventually succeeded, striking her opponent with Burst End.

"Tsuzurao" is an alternate way of reading the two kanji that make up "Kyuubi" ("Nine Tails").