A possible plot twist is that the kiss is part of a prophecy. In the TMNT universe, there could be an ancient prophecy that foretold of a kiss between Leo and April which would either save or doom the world. So after the kiss, they start to discover clues about what this really means for them and their friends. Or perhaps the kiss is seen by an unexpected observer who then spreads false rumors about it, which leads to all sorts of misunderstandings within their community.
One possible plot twist could be that the pregnancy is not what it seems at first. Maybe it's a result of some sort of alien or mutagenic influence that is making April appear pregnant but it's actually something much more dangerous. For example, it could be a parasite that is using her body to incubate its young. Another plot twist could be that Donnie discovers a way to reverse the pregnancy because he realizes that the world they live in is too dangerous for a baby. Or perhaps, the pregnancy reveals a long - hidden connection between April and the Turtles' origin that no one expected.
A common plot twist could be that April was actually kidnapped by someone she thought was a friend. This person could be under the control of a greater evil. It would add an element of betrayal to the story.
One possible plot twist could be that the TMNT turn into dragons not because of some magic spell gone wrong, but because it's an ancient prophecy. They are the only ones who can save the city in their dragon forms from a powerful, otherworldly threat. As dragons, they have new powers like breathing fire or flying at supersonic speeds, which they use to fight the enemy.
In this fanfiction, the plot might revolve around the mystery of how April got pregnant in the first place. Since they are from different species, it could be some sort of magical or scientific anomaly. Donnie would be on a quest to understand it while also taking care of April. They could also have to deal with the reactions of the human world if the pregnancy becomes known. There could be a sub - plot where they search for a safe place to raise the baby, away from both human and mutant threats.
Well, one possible plot could be that Leo discovers an abandoned baby during one of his patrols. He decides to take the baby under his wing and protect it. His brothers are initially skeptical but soon come around. They then have to figure out how to take care of the baby's basic needs like feeding and clothing while also keeping it safe from the various threats in their world.
The other Turtles might be shocked at first. Donnie would probably start analyzing the situation, trying to figure out if it was a smart move or not. Mikey might make some jokes about it, while Raph would be more skeptical and might even be a bit angry, thinking Leo is making a mistake.
Well, a plot twist could be that right after they kiss, they find out that there is a time - travel related issue. Like, their kiss has sent them to a different dimension where they have to work together to get back home while dealing with their new - found feelings. It could also be that the kiss was witnessed by a jealous ex - partner of either Gwen or Kevin, and this ex - partner then tries to break them up in really devious ways. Maybe the ex - partner spreads false rumors about one of them, which causes a rift between Gwen and Kevin.
The kiss might lead to a change in Thor's relationship with other characters. If Thor has a love interest like Jane, the kiss with the Enchantress could create jealousy and conflict. It could also make Thor question his own feelings and loyalties. He might be drawn to the Enchantress' allure but also feel guilty about betraying his friends or his true love.
One possible plot twist could be that the kiss is part of a genjutsu. Maybe an enemy has put Naruto under a genjutsu, making him see Tayuya in a different light and be compelled to kiss her. When he breaks free from the genjutsu, he has to deal with the confusion and guilt.
One possible plot twist could be that their kiss is part of a spell gone wrong. Maybe they were trying to combine their powers to defeat a powerful enemy, and the magic misfired, resulting in an unexpected kiss. This could lead to a series of comical and confusing events as they try to figure out how to reverse the spell without losing their newfound closeness.