Adaptation Expansion: Unlike in canon, here we see the moment when Saki discovers the truth behind his heritage and the moment when his Face–Heel Turn happens.
Arbitrary Skepticism: Yoshi scoffs at the idea of there being anything supernatural in the forest whenever Chung I isn't around, the shinobi-wizard in China at the time.
In canon, the Turtles find sanctuary with Tang Shen and a baby Miwa. Here it is with their grandfather Hamato Yuuta.
While the canon!turtles were sent back in time when Miwa was a baby, here their time-travel excursion (as well as the fall of the Hamato Clan) instead occurs when Yoshi proposes to Shen.
Hope Spot: When Saki finds the Hamato children, he scolds the surrounding ninja for getting worked up over what he thinks are just a bunch of kids in cosplay... then the human-glamour Renet put over Leo, Raph and Mikey wear off.
Yuuta notes Donatello's physical resemblance and Mikey's lack of manners to Yoshi and compares Leo's formal behavior to Tang Shen.
Mikey compares Yuuta's Koan to their father's own zen behaviour.
Parental Sexuality Squick: Everyone (including Donnie himself) chide Donnie for even mentioning any of them being "conceived" due to whatever meddling they start to do.
Ripple Effect Indicator: The turtles are able to tell how radically they change the timeline by their friends vanishing in a picture on Donatello's cellphone.
Shout-Out: The chapter's title is an obvious reference to the 1985 film Back to the Future. Even the premise has some parallels; someone accidentally gets sent to the past before they were born (in this case, all five of the Hamato children), they encounter their younger parents and grandparents (or just their grandfather) and have to make sure that things turn out exactly right or else they cease to exist, using a Ripple Effect Indicator to see if they're doing it right.
Spotting the Thread: At first Yuuta notices that Donatello has a startling resemblance to Yoshi. Then he notices that Leo's shuriken has the Hamato Crest on it, while knowing that it were not stolen or else he would have known. In addition, he notices that they are well adept in his family's fighting style as if they had been trained in it for their whole lives, not to mention that Miwa addresses Saki as Oroku Saki when Saki does not know of his heritage, believing himself to be only Hamato Saki. While he does not have all the facts, he uses all of this to hear them out and trust them in-spite of (in his belief) being Youkai.
Tempting Fate: When Saki reacts to the news that Yoshi and Tang Shen are going to get married with anger, Yoshi admits that Saki handled it better than he thought and that he should sleep with one eye open for fear that Saki would try to gut him later. What are the odds that Saki launches his rebellion later that night?
