This is a possible summary:
Four YouTubers (Mark, Ethan, Tyler and Wade) attempt the "Shocking Sour Challenge", where they eat increasingly sour candies while wearing muscle stimulators that deliver electric shocks to their arms. They start with mild candies like Lemonheads and Sour Patch, then move on to Warheads, which they put in shot glasses and increase the number and voltage with each round. They also try not to make any faces or noises while enduring the pain and discomfort. They experience various symptoms such as sweating, bleeding, twitching, gagging and crying. Bob is off-camera and laughs at their suffering. Wade taps out of the sour part after eight Warheads, but continues with the shocks. Mark, Ethan and Tyler manage to reach ten Warheads and the highest shock level, then end the video by warning the viewers not to try this at home.
Here are the key facts extracted from the text:
1. The text is a transcript of a video where four people (Mark, Ethan, Tyler and Wade) try to eat sour candies while using muscle stimulators.
2. The video is called "The Shockingly Sour Challenge" and it was uploaded by Markiplier, a popular YouTube gamer and comedian.
3. The sour candies they use are Lemonheads, Sour Patch, Sour Skittles, Sour Strips and Warheads.
4. The muscle stimulators have 10 levels of intensity and they increase the level every time they add one more Warhead to their shot glasses.
5. The challenge is very painful and unpleasant for the participants, who make various faces, noises and gestures to express their discomfort.
6. Ethan has food allergies and he has to read the ingredients of the candies before eating them.
7. Wade taps out of the sour part of the challenge after eating seven Warheads, but he continues with the muscle stimulators.
8. Mark, Ethan and Tyler manage to complete the challenge with 10 Warheads and 10 levels of muscle stimulation, but they suffer a lot of damage to their mouths and tongues.
9. Bob is an off-screen person who laughs maniacally at the participants' suffering and occasionally comments on their reactions.
10. The participants advise the viewers not to do this challenge at home or anywhere else, as it is very bad for their health and well-being.