From is a sci-fi horror mystery series by John Griffin that showcases an ordinary small town that traps everyone who enters. There is no way out, as whichever road they take, they come back to the town. The town is further under threat from monsters that look like humans.
Amidst this, Randall becomes one of the passersby, who arrives in the town at the start of season 2. He is initially shown as selfish, but in season 3, Randall heroically alerts the group when some creatures breach the barn area. He also tries to rescue others and is left behind while others are rescued from the creature. He is attacked, with his face severely injured. He astonishingly survives the night after being left unconscious on the hood of the ambulance.
Here is what happened with Randall in season 3 of From

The residents of the town use talisman stones to keep themselves protected from the threat and follow strict rules to survive, with no going out after dark, etc. Randall is portrayed as a muscular guy with a volatile temper and a tendency to be selfish initially, but life in the town transforms him by season 3, when he is seen helping people and surviving a brutal attack by a monster.
Therefore, in season 3, Randall survives what should have been a fatal mauling, but the trauma festers in the coming episodes. The gash on his face becomes symbolic of wounds that never heal inside his head. He starts to hallucinate some buzzing and whispering sounds, suggesting that these are not just noises, but he is psychologically stuck, which is breaking him down.
By reaching for the defibrillator in the season 3 finale, Randall isn’t trying to die; he’s trying to shock away the cicadas, almost like a self-imposed electroshock therapy. This makes his act more tragic than suicidal. From being the most headstrong one, he becomes the most pitiable character in From, as the town has dismantled him from the inside.
Randall is found and taken inside Colony House after the brutal attack in From Season 3
Randall is taken to the Colony House and is treated in the clinic. Though physically patched up, with his wounds stitched and disinfected, he remains deeply traumatized. He writhes in pain and expresses betrayal, accusing Boyd of abandoning him.
Even after waking, Randall continues to suffer from cicada hallucinations. He battles feelings of isolation and guilt, resisting help until Kristi and Marielle intervene, offering him refuge in the clinic so he doesn't have to sleep alone on the bus. Friendship begins to mend as Julie also extends kindness toward him.
By the Season 3 finale, Randall reaches a dire emotional breaking point. His trauma, ongoing hallucinations, and alienation drive him to a reckless act: he attempts to use a defibrillator on himself. This grim decision underscores just how deeply unsettled he remains by the horrors he’s endured and witnessed.