Obito Uchiha

Tobi (whose original name is Obito Uchiha) is the central antagonist of the Naruto franchise and the leader of Akatsuki. He is a fallen hero from Konohagakure, the Village Hidden in the Leaves, who follows Madara Uchiha's goal for his own gain. Despite appearing late in the story, Tobi orchestrated the attack of the Nine-Tailed Demon Fox, the Massacre of the Uchiha Clan, and most of the conflict driving the story from behind the scene.

Kazekage Rescue Mission
As Tobi, he assisted Zetsu with locating Sasori's body. Once he found it and took Sasori's ring, he expressed his belief that he would now be able to join Akatsuki. They next tracked down Deidara's disembodied arm with its ring still attached. Tobi initially believed Deidara had also died, only for Deidara to appear before them shortly afterwards. Tobi was somewhat relieved to see him, but was concerned for both his well-being and capability with rather offensive jokes, provoking Deidara to strangle him with his legs.

Three-Tails' Appearance
Tobi was indeed accepted into Akatsuki as Sasori's replacement, partnered with Deidara. He was assigned to capture the Three-Tails. In the anime, Deidara treated Tobi to some dango before the mission, a ploy to get him to remove his mask. He turned away while he ate, preventing Deidara from seeing anything. They split up after eating and Tobi eventually found Konoha shinobi using the Four-Corner Sealing Barrier, which he deduced was meant to seal the Three-Tails. He informed Deidara of his discovery and they approached and killed the two Anbu put in charge of the sealing.

When they located the Three-Tails, Tobi tried to convince Deidara to fight it in his place. When the Three-Tails chased Tobi, Deidara used his Explosive Clay on it while it's distracted. The rest of the battle went unseen. After they defeated the Three-Tails, Tobi claimed responsibility for the beast's capture, saying his technique was flawless and that it made sense to assign him to the mission. Deidara retorted that it was actually his clay that defeated the Three-Tails. Tobi, unconvinced, fell asleep during Deidara's argument. Deidara "woke him up" by detonating a clay bomb next to him.

When they got the Three-Tails to an Akatsuki base, the Akatsuki members convened and sealed it. When they were done, they also sealed the Two-Tails (the Two-Tails is sealed before the Three-Tails' capture in the anime).

Superpowers
I can sense his presence. Why? Because I can tell from their movements that my Kikaichuu are still draining his Chakra. The Insects that were tracking his Chakra lost him completely. No its not the Body Flicker technique. Why? Its because my insects would've followed his direction anyway. He managed to teleport without using any seals, summonings, or markings? That means he has a Space-Time ninjutsu even better than the Fourth 's. His body completely disappeared. Can he simply vanish out of existence? If he can actually disappear at will, I wouldn't be surprised if he can do it to just his body parts as well. It would explain why only a part of his body managed to bypass earlier attacks. To us, it only looks like they made contact, but they actually missed their marks. So basically, he's not dodging the attacks. They're just going straight through him.
 * 1) According to Minato, Tobi's Teleportation Jutsu surpases his, and the Second Hokage's.
 * 2) Chakra
 * 3) Enlightenment
 * 4) Walk on Water Technique
 * 5) Sharingan
 * 6) Teleportation
 * 7) Transcended

Jutsu

 * 1) Asura Path
 * 2) Chakra Receivers
 * 3) Chakra Transfer Technique
 * 4) Clone Jutsu
 * 5) Crystal Ball Jutsu
 * 6) Deva Path
 * 7) Fire Style: Bomb Blast Dance
 * 8) Fire Style: Fire Ball Jutsu
 * 9) Fire Style: Phoenix Flower Jutsu
 * 10) Gedo Art of Rinne Rebirth
 * 11) Genjutsu: Sharingan
 * 12) Human Path
 * 13) Infinite Tsukuyomi
 * 14) Izanagi
 * 15) Kamui
 * 16) Limited Tsukuyomi
 * 17) Mangekyō Sharingan
 * 18) Naraka Path
 * 19) Ninja Art: Blockade Technique
 * 20) Ninja Art: Whac-A-Mole Jutsu
 * 21) Outer Path Chains
 * 22) Preta Path
 * 23) Rinnegan
 * 24) Rinne Six Paths
 * 25) Sharingan
 * 26) Sealing Jutsu: Nine Phantom Dragons
 * 27) Six Crimson Ray Formation
 * 28) Six Paths Jutsu
 * 29) Six Paths Sage Technique
 * 30) Six Paths Ten-Tails Coffin Seal
 * 31) Substitution Jutsu
 * 32) Summit Enlightenment
 * 33) Summoning Jutsu: Gedo Statue
 * 34) Summoning Jutsu: Nine-Tailed Demon Fox
 * 35) Tailed Beast Ball
 * 36) Tailed Beast Chakra Arms
 * 37) Tailed Beast Transfer Technique
 * 38) Tail Releasing Method
 * 39) Teleportation Jutsu
 * 40) Transformation Jutsu: Transform
 * 41) Truth-Seeking Balls
 * 42) Uchiha Flame Formation
 * 43) Uchiha Reflection
 * 44) Wood Style: Cutting Sprigs Jutsu
 * 45) Wood Style: Great Tree Spear
 * 46) Wood Style: Underground Roots Technique

Ninja Tools

 * 1) Benihisago
 * 2) Gedo Statue
 * 3) Gunbai Uchiwa
 * 4) Kohaku no Johei

Goofs

 * Deidara shows up wearing no ring when Tobi picks up his arm, but in the next scene, Deidara is wearing a ring on his index finger and his arm is gone, even though Tobi was holding it beforehand.
 * In the English dub of this episode, during the scene in which Tobi laughs after thinking Deidara blew himself up, the former's head movement is shown not to have changed from the original Japanese version to rhythmically match with the laughter of Tobi's English voice actor.
 * In the overhead view when Zetsu and Tobi are looking for Sasori's ring, the white and black sides of Zetsu's body are reversed.

Trivia

 * According to Kisame Hoshigaki Tobi was a great Escape Artist.
 * This episode marks the first appearance of Sai outside of the teaser from episode 1. It also marks Tobi's first appearance.