To some extent, it is popular. There are many online platforms where MHA adult fanfiction can be found. The popularity might stem from the fact that the MHA world has a rich cast of characters and a complex universe. Fans who enjoy adult - oriented storytelling might use these characters to create their own narratives that are more in line with their interests in terms of relationships, power dynamics, and personal growth, all with an adult twist.
Several characters have met their demise in the MHA manga, but it's a bit complex to list them all precisely. Some of the notable ones include [mention specific characters if known].
I think it's hard to say for sure. There are a few characters who could potentially be the traitor, and it's all part of the mystery and suspense of the story.
Definitely not a true story. FNAF is a work of fiction that takes place in a fictional world with its own set of rules and scenarios. It's all about creating a thrilling and immersive gaming and storytelling experience, not reflecting reality.