Hi Xen! Thanks for dropping by planDisney.
Oh my stars, sounds like you have a fun night ahead of you as Disneyland Resort
welcomes the class of 2023. As a fellow Star Wars fan, I understand wanting to bring your lightsaber for the festivities. After all, it is an elegant choice for a more civilized age. While it is possible to build
custom lightsabers and purchase ready-made ones at the parks, they also come from other corners of the galaxy, which shouldn't necessarily be a problem for Jedi or Sith Guests.
The good news is Disneyland Resort
policy states so long as your lightsaber doesn't resemble a real-life weapon, it should be allowed in the parks. However, security ultimately determines what qualifies as fantasy and what looks like a weapon, so it is up to their discretion. Based on what you've described, I'd guess you'll be okay. Just be sure your kyber crystal--or batteries--are fresh for a long night of Force-enhanced lightsaber wielding. You wouldn't want it to go out!
May the Force be with you.
Elizabeth