Karai searches for the Kuro Kabuto, claiming to be the heir to the Foot Clan, but she encounters an old rival.
- Antagonist Title: The titular character is Hattori Tatsu, an old mentor of Karai who is now fighting her and Tiger Claw to retrieve the Kuro Kabuto.
- Back from the Dead: Kavaxas uses his powers to bring Rahzar/Chris Bradford back from the dead in this episode after Leatherhead had drowned him in "Requiem". For Shredder, however, he needs both his heart and the mutated Kuro Kabuto.
- Big Bad Ensemble: Tatsu is a Foot Clan member, but he's working on his own and has no relationship with Tiger Claw in his quest to retrieve the Kuro Kabuto. He's also the victim of an Eviler than Thou from Kavaxas.
- Chekhov's Skill: At the start of the episode, Leo darts behind Raph after Raph talks back to him and pressure points his neck to knock him out. He uses this exact same skill to disable Tatsu's abilities when Tatsu is distracted by Karai, allowing her snake form to pummel Tatsu into submission.
- Evil Laugh: Rahzar gives off a rather epic laugh along with a "I live!" proclamation when Kavaxas revives him.
- Eviler than Thou: For all of Hattori Tatsu's skills, he is immediately and effortlessly killed by Kavaxas when the demodragon comes in to steal the Kuro Kabuto himself.
- Family-Unfriendly Death: Tatsu seems to have the life drained out of him by Kavaxas. What makes it really unfriendly is seeing his body afterward.
- Handicapped Badass: Hattori Tatsu is blind, but that doesn't hinder him at all until explosives and a pressure point attack from Leo disable his other senses.
- Internal Reveal: The heroes learn that Tiger Claw wants to use Kavaxas to resurrect The Shredder.
- Oh, Crap!: Tatsu's reaction when Leo manages to disable his hearing, leaving him completely blind and helpless.
- Macguffin: The Kuro Kabuto acts as this in this episode, as all three factions attempt to reclaim it.
- Mythology Gag: Tatsu was the name of Shredder's right hand man in the live action movies of the 90s. In The Secret of the Ooze, Tatsu attempted to claim leadership of the Foot following Shredder's apparent death, similar to his attempt here.
- Nice Job Breaking It, Hero: Tatsu reveals that Karai tried to have him killed during her attempt to seize control of the Foot, and so in retaliation he's in New York not only to claim the Kuro Kabuto (and with it the leadership of the Foot Clan) but to kill her and anyone and everyone she knows.
- Serious Business: Leo nerve-pinching Raph when Raph pushes back against his orders, indicating that now that he's head of the family, he has no interest in engaging in Raph's usual arguing. It's important to note that he's fine with Raph or the others discussing or disagreeing with him, as they will do in other episodes - but he's not going to tolerate a tantrum.
- Shout-Out: April picked up a book about Demodragons from "Ray's Occult Bookshop."
- So Last Season: In terms of his abilities, power and skill, Tatsu is roughly equal to the Shredder circa Seasons 1-4 (before his mutation into the Super Shredder). However, the Turtles, Karai, Shinigami, Casey and April are actually able to defeat him in a straight up fight due to the fact they're all a lot stronger, skilled and experienced from before.
- Sorting Algorithm of Evil: Tatsu is comparable to pre-mutation Shredder in terms of his skills and strength. However, Kavaxas so outclasses him that Curb-Stomp Battle doesn't even begin to cover it.
- Took a Level in Badass: For the Turtles and their allies. Tatsu is roughly as powerful as the Shredder was prior to his mutation, but while he gets a few good shots in (enough that Shinigami and Casey have to be hospitalized and the other Turtles treated) they manage to outright defeat him. In comparison, Shredder spent almost 4 seasons being nigh-unbeatable (at one point actually fighting the combined might of the Turtles and the Mutanimals to a standstill), and that was before his mutation.
- Underestimating Badassery: Karai grasped this hard with Tutsu. She tried to kill him and learned the hard way just how incredibly skilled and dangerous he was. Leo even lampshades this trope at the end by recalling a lesson from Splinter about how underestimating your enemy is a deadly weakness.
- Tutsu himself grasped this in regards to the Turtles and their allies teamwork, resourcefulness, and quick wittedness. Spending the majority of the fight easily knocking them around, and even hospitalized Casey and Shinigami, he thinks they're too weak to stop him. This literally comes back to bite him when they use Casey's exploding pucks to distort his sharp hearing long enough for Karai to get close and lock swords, all while Leo sneaks up behind him, with Tustu unable to see him and nerve strike him, disabling his abilities and allowing Karai, in serpent form, to soundly defeat him.
- Unexplained Recovery: Fishface is shown at the beginning of the episode perfectly fine and retrieving Rahzar's body. Though it's possible he was just revived by Kavaxas before this episode.
- What the Hell, Hero?: Leo's reaction when Tatsu reveals that Karai tried to have him assassinated when she tried to reorganise the Foot. Part of the reason he's in New York is for revenge, while the other is to stake his own claim as the new leader of the Foot.
- You Can't Thwart Stage One: The Kuro Kabuto ends in Tiger Claw's possession bringing the Foot Clan one step closer to bringing back Shredder.
