Unlike Naruto—whose potential got downgraded to "dead last" due to the Nine-Tails' chakra interference—Izayoi has become insanely powerful ever since obtaining the Otsutsuki bloodline. Not only does he have staggering potential, but his foundations are unbelievably solid.
Thanks to the Byakugan's ability to see chakra pathways, the Hyuga clan naturally excels at chakra control. After Izayoi awakened the Byakugan, he unlocked the "Chakra Control" entry as well. And before even starting at the Academy, he'd already learned to walk up trees and run on water. Forget the basic Three Academy Jutsu—he could already handle his parents' B-rank Shadow Clone Jutsu and a few basic elemental ninjutsu. He was just like Uchiha Itachi, who mastered graduation-level skills well before even entering the Academy.
So, no surprise: Izayoi aced the Academy entrance exam and got first place. Because of that, he was assigned to Class 1-A, right alongside the "Konoha 9."
When he arrived in the classroom, a bunch of students were already inside. Izayoi glanced around and locked eyes with a certain girl who spotted him too—she looked thrilled. Smiling slightly, he headed straight for her. The desks were long, each seat meant for three people. The girl was in the middle, with empty seats on both sides.
"Yo, we meet again," Izayoi said, sitting down next to her. Then, teasingly, "I see the runaway princess had no trouble with the entrance exam."
"Iz… I-Izayoi-kun."
(Hinata trips a bit over his name.)
She didn't dare make eye contact and kept her head down, poking her fingers together. Even so, she was obviously happy and excited. It turned out she'd guessed right—the "Izayoi" on the enrollment list was the same Izayoi who'd once helped her.
"Looks like we're seatmates now. I look forward to learning with you, Hyuga—no, Hinata." Izayoi smiled at the girl, whose cheeks and ears were bright red.
Hinata gave Izayoi a quick sideways glance, but the moment their eyes met, she looked down again. "I…I look forward to it, Izayoi-kun," she mumbled.
She didn't notice the hint of intensity in Izayoi's eyes. In Izayoi's view, five colored "bubbles" were floating around her. Among them, the biggest and brightest was a red bubble:
[Princess of the Byakugan (Red)]
[Kekkei Genkai: Byakugan (Purple)]
[Jonin Aptitude (Blue)]
[Otsutsuki Bloodline (Blue)]
[Chakra Control (Blue)]
"Princess of the Byakugan"—that was the main reason Izayoi had approached Hinata. It was why he waited outside on that snowy night after Hizashi's funeral, anticipating she'd run away from home, and ultimately earned her trust. The moment Izayoi saw that talent entry, he decided to hijack both Naruto's "Chosen One" role and Toneri's ambitions.
Just like how Asura and Indra's reincarnations can combine forces to awaken the Rinnegan, Toneri Otsutsuki and Hinata only need each other's power to awaken the Tenseigan. Because both of them have a bloodline and Byakugan purity that's off the charts, it's basically guaranteed they could awaken the Tenseigan. In the original timeline, Hinata could have overturned her destiny if she'd managed to get chakra from Toneri Otsutsuki—but that's nearly impossible.
So as she was then—"Princess of the Byakugan" with only a Blue-tier Otsutsuki bloodline—Hinata's max potential was around elite Jonin. But now her fate was changing. Thanks to Izayoi's Red-tier Otsutsuki bloodline, his chakra might just help Hinata rewrite her destiny. And Hinata's Red-tier talent would let Izayoi gain Tenseigan power. They were literally a perfect match.
Izayoi just said a quick hello to Hinata and then fell quiet. This was only his second time ever meeting her. Hinata was already learning the Gentle Fist at six, getting overshadowed by Neji and slowly disappointing Hiashi, which caused her to become shy and withdrawn. Three years ago, she was also shy, but she'd still been willing to look Izayoi in the eyes when talking.
At least Hanabi wasn't old enough yet for Hiashi to give up on Hinata entirely and focus on the younger daughter. A little encouragement could really help Hinata's confidence. But that's another challenge: as the Hyuga heiress, Hinata rarely leaves the clan compound except for classes, and even when she does go out, she's accompanied by green-vested Hyuga guardians. Being alone with her is practically impossible. Izayoi would have to come up with a plan.
He propped his chin on one hand and tapped the desk lightly with the other. Meanwhile, Hinata was peeking over at his thoughtful expression. The admiration she felt for him surged up all over again. She looked up to Izayoi. She was the type to get lost as soon as she left home, while he could wander around in the dead of a snowy night with no problem. He acted so grown-up, and his entrance exam score was top of the class. If she were that capable, maybe her father wouldn't be so disappointed in her. Plus, aside from Neji, Izayoi was the only other kid around her age she'd ever really known. Even after three years, she hadn't forgotten the black-haired, blue-eyed boy with his chubby baby cheeks—Izayoi.
Hinata really wanted to chat with him, but she was too nervous to even open her mouth. She couldn't help it—she just wasn't that confident yet.
Izayoi, on the other hand, had snapped out of his thoughts—he'd spotted his next targets: Uzumaki Naruto and Uchiha Sasuke. Bubbles floated around them, too, each containing a red bubble like Hinata's.
Naruto's talent entries were:
[Sage Body (Red)]
[Super-Kage Aptitude (Gold)]
[Uzumaki Bloodline (Purple)]
[Otsutsuki Bloodline (Blue)]
Izayoi didn't see anything labeled "Asura" or "Nine-Tails," but the Red-level Sage Body and the Uzumaki bloodline showed that Naruto's Sage Body was on par with a pure Otsutsuki bloodline—no surprise, given it originally came from Hagoromo and his son, Asura. And on top of those four, Naruto also had half of the Nine-Tails sealed inside him.
Compared to that, Sasuke's entries looked a bit weaker:
[Sage Eyes (Red)]
[Kage-Level Aptitude (Purple)]
[Uchiha Bloodline (Purple)]
[Otsutsuki Bloodline (Blue)]
"Princess of the Byakugan" is unimpressive if she never evolves. By the same token, "Sage Eyes" isn't worth much if it doesn't awaken. Without Itachi's eyes or a boosted Indra chakra, Sasuke would be stuck at mid-level Kage at best, ultimately going blind from overusing the Mangekyo. Only when he obtains the Eternal Mangekyo or activates the real power of Indra's chakra—thus gaining virtually unlimited eye power without swapping eyes—would his aptitude hit Super-Kage.
Just like how Madara was always smacked down by Hashirama, Naruto might seem weak right now, but once he starts ramping up, he'll surpass Sasuke—who's been grinding the entire time—in a heartbeat. That's how it was for all six years at the Academy, and the same dynamic carried on during Shippuden. That's simply the difference natural talent (and a few "cheats") can make.