Fans have seen Gendry in Game of Thrones when he stumbled upon Arya at King’s Landing. He has become a fan favorite, but unfortunately not all fan favorites survive the show, as we know all too well.
Game of Thrones clearly has this enjoyment of killing off fans beloved characters: Ned Stark, Robb Stark, Catelyn Stark, and so on. With Gendry's blacksmith skills he could be of aid to Jon Snow, although him joining the Night’s Watch for the upcoming battle with the White Walkers could be the end of Gendry if he decides to fight.
However, there are other possible reasons for his death.
Whenever Gendry and Arya have an encounter, it seems Arya takes a liking to him. Joe Dempsie, the actor who plays Gendry, acknowledged his character awakened Arya’s sexual feelings. If the show does put the two together, it's likely not going to be a happy ending for him. More often than not, couples in the show get killed off.
By creating weapons of destruction for Jon Snow he already has a path leading to death. Cersei could end up coming over to the North and see that such a well skilled blacksmith is working for her opposing team. Which then, Cersei could decide to end him.
Now this is where things get more complicated for Gendry.
There is also a fan theory claiming Gendry could be Cersei’s son. In season one, Cersei told Catelyn Stark her firstborn was a boy, a "little black-haired beauty" who died after his birth. This could actually be a lie. Even though she was married to Robert Baratheon, she goes after her beloved brother Jaime.
She could've sent Gendry away in order to get her son with Jaime, Joffrey, to take the throne. Is it still confusing?
Alright, here’s how it could've worked: Cersei swapped the healthy baby with a dying one while her husband was away, only to present the dying child to him when he returned. This would explain how Gendry somehow gets a job with the most impressive armorer in King's Landing.
We also learn Tobho Mott took Gendry in after a stranger paid twice the usual apprentice fee. Cersei must have been that stranger. (mind blown!)
If all this is true, then a plot twist could happen where the very people Gendry became allies with decide to kill him. The season finale will soon rise upon us. Only then will fans know the true fate of Gendry.