Opinions That Led to a Strange Conclusion

So... Gon and Killua, as well as 18 other people, received a strange email, which blew up in their faces 15 seconds later, which told them that its needs help. While threatening them to come. Then, they get pushed into a job they have to complete before they can go back to their world. Though, something is wrong with the sender's nen. T for Holocaust information.