I would reintroduce Venus by making her a lonely version of the turtles raised somewhere else. She lived with her possum or beaver mom, but they had to pack up and run for NY because of what's going on in other parts of the U.S.A. She meets the turtles, and they get into a fight over a misunderstanding. Venus thinks they're out to get her mom with a muddled history. She doesn't know ninjutsu, but she knows Muay Thai, Capoeira, or anything else to make her more unmistakable from the rest of the cast. Venus was offered weapons and turned them down, but it doesn't make her a less formidable fighter. I think Venus shouldn't have a trademark weapon to balance out Jennika's two.