Summary
- The flickerphase blade, a modified lightsaber that extends and retracts randomly, was considered dishonorable and banned by the Jedi Order due to its unblockable attacks.
- Flickerphase blades were cheaper than standard lightsabers and were seen as broken lightsabers. They were sold for around 5,000 credits on the black market.
- The unpredictable nature of flickerphase blades made them a risk for both enemies and wielders, as they could cause injury.
Despite being one of the most dangerous and versatile weapons in Star Wars, there are some versions of the lightsaber the Jedi banned for being too powerful. Ever since its introduction in A New Hope, the humble lightsaber has been altered and modified from the standard singled-bladed lightsaber. From Darth Maul’s iconic double-bladed lightsaber to Kylo Ren’s crossguard lightsaber, the franchise continues to expand just how creative Force-users can get with a simple kyber crystal. Nevertheless, some of the coolest lightsabers in Star Wars aren't seen in the movies and are relegated to Legends.
Despite Legends having a plethora of interesting lightsabers, a couple of deadly blade designs have seeped still into canon. However, deviating from the standard lightsaber design carries a lot of risk. According to Huyang in The Clone Wars, the simple mistake of inverting the emitter matrix could cause a lightsaber to backfire and explode. And while most Jedi Younglings make similar mistakes while crafting their first lightsabers, other rogue tinkerers intentionally change their lightsaber designs to create new variants.
Your browser does not support the video tag. Star Wars Canon Introduces The "Flickerphase Blade" 
One extremely dangerous lightsaber variant was the flickerphase blade. This model of lightsaber looked almost indistinguishable from a regular lightsaber, except the blade was modified to extend and retract randomly, creating a “flickering” effect. Because the blade was constantly turning itself off and on, it allowed the wielder to slip past an opponent’s defense with ease. In other words, just as an enemy was about to defend themselves with their own saber, the flickerphase blade could flicker straight through their counter.
The flickerphase lightsaber comes from the Knights of Fate sourcebook, which is a canon book used in the Star Wars: Force and Destiny roleplaying game. And while this means the flickerphase blade belongs to one of the more obscure sides of the galaxy, it also means the films and tv shows may reference it at some point. The films have already experimented with unstable lightsaber modifications, such as Kylo Ren’s lightsaber with its cracked kyber crystal, giving the blade a crackling energy.
