Seals

Gaara had once placed a seal at the highest scouting border of Sunagakure, in case he ever wanted to escape or return quickly. He couldn't use it on a whim; the seal was too complex to create and required intense focus and chakra. But with natural energy, he could now feel its presence deeply, resonating with him as its creator. This seal wasn't quite the famed Flying Thunder God Technique, but it represented his own take on it. Gaara had longed to experience the jutsu's instantaneous teleportation to a marked location—not for necessity, but for the sheer exhilaration of mastering such a powerful technique.

Over time, he discovered that Shukaku, the One-Tailed Beast, possessed a natural affinity for fuinjutsu and juinjutsu—types of sealing jutsu. Gaara originally thought these two practices were different, but after Shukaku taught him the basics of sealing, he realized the applications overlapped more than he'd expected. Inspired by the knowledge Shukaku shared, Gaara began developing his own version of the Flying Thunder God Technique.

Although the academy taught mostly ninjutsu, he'd experimented with seals on his own, using the one that held Shukaku within him as a case study. He crafted theoretical designs, but it wasn't until after his first mission with Lady Chiyo that he dared to test them practically. Trial and error revealed critical aspects: the modified seal he was creating needed four components—an entry point, an anchor, a seal, and, ideally, a network.

The entry point acted as a door or marker, the anchor stabilized the technique, the seal functioned as the lock, and the network could be viewed as the underlying structure. While the network wasn't strictly necessary at his level, Gaara was intrigued by its potential and set a shadow clone in the desert to work on it using natural energy.

At the same time, he kept some natural energy tightly contained within himself to fuel his experiments. Now, his clones stood side by side: one transferred natural energy to the other, leaving itself with only enough to sustain the shadow clone while the recipient absorbed chakra afresh. Both clones now had a slightly different appearance, though not drastically so.

For now, Gaara's custom teleportation seal could only be used once before it "broke." This wasn't a flaw; rather, it was due to the strain his creation put on the seal. He and Shukaku were building a unique system of "sand doors" that only he could access, each powered by Shukaku's chakra as the foundation. The entry point of each door connected to Gaara, who served as the hub. Shukaku's chakra signature matched Gaara's closely enough that Gaara could use these "doors" without the tailed beast's direct presence. Shukaku's involvement strengthened the anchors, allowing the sand doors to stay open longer and reach across greater distances.

Yet, these doors were a one-way ticket—they could only pull him to a marked spot and couldn't serve as a two-way path. Gaara's current understanding of seals wasn't advanced enough to fix this limitation. When he teleported, the seal bore a heavy strain as it connected two distant points in space, causing it to shatter after one use.

Gaara was still the hub, the seals acted as entry points, and the anchor—his chakra—reinforced the structure. While someone could theoretically trace the seal back to him, it couldn't be used to teleport to him because the entry point required his unique chakra signature. Recreating it would be nearly impossible mid-battle.

As Gaara's experience grew, he sensed that natural energy held the key to stabilizing and sustaining his seals for multiple uses. Testing this theory would be the next step.