“Trials of the Darksaber” gave us so many delightful insights into lightsaber combat and I am so happy for it.
1. It confirmed the “lightsabers have weight” argument that was postulated after TFA: the looping energy gives resistance against the hand, demanding extreme focus and skill.
2. The energies of a lightsaber blade call to one another. This was my favorite revelation, as it explains that age-old gripe about “Why don’t they just slide the blade down, there’s no handguard!” and “The blades wouldn’t lock like that!” It also points out why a combatant can’t just extinguish the blade to break a lock and then flip it on again for a kill–there’s more to it than two lines in space. The lightsaber is an extension of the Force and its wielder, and seeks to match other energies.
This also explains why a lightsaber can catch Force Lightning–the dark magical energy is drawn to the magical blade.
3. Lightsabers are now officially magical objects. The Darksaber straight-up BIT Sabine when she was being reluctant with it, and even seemed to influence her emotions–while I am not dismissing her emotional triumph throughout the episode, I am positing that the weapon helped to channel her feelings.
This revelation is also, of course, not only relevant to the Darksaber. This could explain why Jedi and Sith don’t just turn off their opponent’s weapon or rip them from their hands–the weapon itself will resist. This would also conform to the Rey Skywalker hypothesis in that she was able to call Anakin’s lightsaber to her hand because she, too, is his grandchild–born of the man who wielded it first. The sword chose her.
Sentient lightsabers could even give further insight into the legacy of the Kyber Saber, but that is a matter for another day.