It could be a rogue scientist who wants to take the lab rats back for his own evil experiments. He might see the girl as an obstacle in his way and try to get rid of her.
A powerful corporation that wants to use the technology behind the lab rats for profit. They see the girl and the lab rats as a threat to their plans and send their agents to capture them and shut down any opposition.
Perhaps a jealous rival of the scientists who created the lab rats. This person wants to prove that the lab rats are a danger to society and will stop at nothing to expose them, even if it means harming the girl who is protecting them.
Maybe a malfunctioning android created in the lab could turn against Chase and be the main villain. It could accidentally cause him harm during a routine check - up or experiment, and then continue to pose a threat as it goes haywire and tries to prevent anyone from fixing the situation.
Maybe the girl discovers a hidden connection between her family and the creation of the lab rats. This leads to a journey of self - discovery as she uncovers secrets about her past and the origin of the lab rats.
Obviously, Tasha would be a main character as she is the one who is pregnant. Donald could also be a main character as he is her husband and would be involved in the pregnancy journey. The bionic kids, like Chase, Bree, and Leo, would also be important main characters as they are part of the family and their reactions and actions would play a big role in the story.
The main characters are Adam and Bree. Adam is typically portrayed as strong and a bit of a brute at times, but with a good heart. Bree, on the other hand, is fast and intelligent. Together, they make an interesting pair in the fanfiction world.
Well, of course, Daniel is a main character. He is often the focus as the story usually revolves around his actions and his relationship with the other bionic characters from the Lab Rats series.
Chase and Adam could be great main characters in a gay fanfiction. Their different personalities - Chase being more intelligent and Adam being more brawny - could create an interesting dynamic in a romantic relationship. They already have a strong bond as brothers in the original show, and it could be developed into a romantic one in the fanfiction.
Maybe an evil scientist from the Lab Rats' world who has heard of Naruto's godlike powers and wants to harness them for his own experiments. He could create powerful robotic minions to fight Naruto and the Lab Rats. This scientist could be jealous of the Lab Rats' abilities and see Naruto as a new source of power to take over both worlds.
It could be a new teacher at the school who has very strict and old - fashioned views. This teacher doesn't believe in the progressive teaching methods that Riley and Maya want to implement, and constantly tries to undermine them. For example, the teacher might try to get their classes cancelled or their teaching materials removed.
The main characters are usually the Lab Rats themselves. They are the ones with superhuman abilities and unique personalities. Each of them brings their own skills to the table whether it's super strength, super speed, or intelligence.
Obviously, Taylor and Leo are the main characters. Taylor is often portrayed as a smart and independent character. Leo, on the other hand, is usually shown as someone who is kind - hearted and has a good relationship with the lab rats.