maybe the prison field doesn't use "magic" but instead uses something like a holy power think darksouls and how magic is split into different categories such as miracles and sorcery the magic nulification would block sorcery from being used but not the miracle that is prison field that's just my best way of bullshitting out of the fact that they did magic in an anti magic barrier
@Zaronax heat resistance is not tensile strength. starlite can resist a propain blowtorch but i can break it with my bear hands
even if it doesnt penetrate the skin or kill them they still follow physics so they will get knocked back or down and eventually they will die from internal bleeding or bruising and besides its not like every enemy army is made up of uber powerful enemies even in the stongest of armies a majority of its makeup is "weak" grunts who would be very killable via bullets
No, I think it is neccessary in the LN/manga/anime version to do this. In the WN there were no Otherworlders involved in the attack, meaning that to Rimuru it was like his impression of the Fantasy-world humans became tainted while his impression of those coming from his former world was still "clean", which might come across as "Japanese people are good! Japanese people do no evil!", but the LN/manga/anime version fixes it by having Japanese people involved in the attack, meaning there won't be a loophole/excuse for Rimuru to view humans from different worlds differently from each other.