WARNING: The following article contains spoilers for Star Wars: The Rise of Kylo Ren #4, by Charles Soule, Will Sliney, Guru-eFX and VC's Travis Lanham, on sale now.
Before Kylo Ren could become one of the most powerful Dark Side, Ben Solo had to fall away from the Light Side, and Star Wars: The Rise of Kylo Ren shows just how that descent happened.
Over the course of the miniseries, Ben Solo has fallen in with the Knights of Ren, who are led by the charismatic Dark Side user Ren. Although Ren was instrumental in turning Ben Solo to the Dark Side, Kylo uses Force lightning to kill him in Star Wars: The Rise of Kylo Ren #4.
Ren discovered Kylo when he still went by Ben Solo, training as a young Jedi Padawan under Luke Skywalker. Even then, Ren sensed the potential in Kylo and extended an offer to become one of his knights if the boy ever so desired. When the Jedi Order fell and Kylo discovered the turmoil that would define his life, he decided to take Ren up on his offer.
While joining the Knights was a major step for Kylo, it still wasn't enough. During a mission where the Knights encounter Kylo's former Jedi companions, Ren commanded Kylo to prove his loyalty by killing his friends, even though they still held out hope that Kylo would return to the Light Side. When Kylo found himself hesitating, Ren made the decision for him and snapped the Jedi's neck with the Force, but that would be the last act Ren would ever perform.
Kylo unleashed the full fury of the Force on Ren, as he felt the simultaneous pulls of the Light Side and the Dark Side in opposite directions. The disturbance that Kylo felt in the Force was so great it resonated throughout the Galaxy, with his mother Leia sensing something was wrong and Rey feeling a sudden chill despite standing in the desert of Jakku. The disturbance came as a result of Kylo finally claiming his place in the Dark Side, stabbing his lightsaber into Ren's chest while striking him with Force lightning.
While he never showed the ability to use Force lightning before, it's appearance here helps communicate Kylo Ren's shift in his allegiance, and it's presently the only canon instance of Kylo using such an ability. Previously, Force lightning was a skill reserved for only the most talented Dark Side users like Emperor Palpatine, who may very well be the strongest Sith the Star Wars canon has ever seen. His protege Count Dooku also wielded the lightning adeptly, but Kylo's use suggests that the ability may be more about emotion than control.
In The Rise of Skywalker, Rey had a similar outburst of power, struggling over control of an escaping ship with Kylo. As both tugged at the ship with the Force, Rey's sudden fury unleashed a bolt of Force lightning from her hand that decimated the ship entirely. The moment signaled her own flirtation with the Dark Side. With this particular bit of Kylo's past revealed, it's clear that the link between the two goes back much further than just the most recent film.
While Kylo Ren's ultimate fate was revealed in The Rise of Skywalker, this revelation is one of many in The Rise of Kylo Ren that details just how far and how fast Ben Solo fell away from the Light Side. Even though the original Ren never appeared on the big screen, his death marked an irrevocable turning point in Kylo Ren's rise.