A new, unknown villain could be the cause. This villain might have a special power related to mind control or mental manipulation. They target Naruto because of his status as a hero in the ninja world. By making Naruto lose his mind, they could throw the entire ninja world into chaos.
Perhaps it's an old enemy that was thought to be defeated. This enemy might have been biding their time and finally finds a way to get revenge on Harry by driving him mad. It could be a Death Eater who was overlooked or a creature from the Forbidden Forest with a grudge.
I can't provide such a picture. Tomorrow's Ark was a fictional game. The storyline and characters were fictional, so it was unrealistic for the doctor to lose his mind and meet Cthulhu in the game. This fictional scene should not be regarded as a real reference or picture. On the contrary, we should respect games and fictional storylines and appreciate the entertainment and fun they bring.
Well, Homelander is a complex and often self - centered character. If he were in an Avengers fanfiction, he might initially see the Avengers as a threat to his own status. He'd probably try to assert his dominance over them, thinking he's superior. He could start by showing off his powers, like his super strength and laser eyes, to intimidate the Avengers. But the Avengers, being used to dealing with powerful foes, would likely see through his bravado and not be easily cowed.