I love seeing kids get into this because I remember when I was a kid and I was getting into it. I grew up with Ezio Conner and Altair. Black Flag came along and then there was Assassin's Creed Rogue after that everything just kind of went to crap. I like your design to get the blade to shoot out immediately. I don't like that it lacks a locking mechanism. I've been studying this technology for a very long time. Probably too long. There was a very old channel from a long time ago called Abonude. Anyway he used to use a 90-degree locking mechanism. I think you might be able to work that in with this project on the very tip of your hidden blade slot with a paper clip at a 90°. And all you have to do for the blade is drill a small hole and go over it with super glue for structure. Hypothetically when your blade shoots forward it will be under the catch of that paperclip allowing you to have it lock in place. You're not too far off from having a real one now great job.
That looks really cool. I’m gonna attempt to make it but instead of cardboard, I’m gonna make it out of wood. But if the wood isn’t turning out that well, I’m just gonna use a wooden blade, so it doesn’t bend as much. and make the rest out of cardboard.