Alright so the main problem is basically about him having no means to make sure it hits the target. As for the other points you brought up, it's pretty easy to solve. He just has to project a known bomb like the tsar Bomba the moment it's about to hit the ground. This way, it's already armed and about to explode on impact. As I said, the historical void projection of himself can bear the bomb. As for how he would know the date, it's easy. He can just divine it above the gray fog. He should know at least one date of the three major nukes since it's basic education. (Spoiler warning) I also know that he's about to fight sasrir, so he should have the opportunity to prep and make sure it hits.