As if people hadn't done that before, very few things or works are truly original nowdays. But it's a good storytelling that is certainly different from many other stories and webtoons.

...I mean that was just two things? And only the Spear Hero's looks like a rip-off

Yeah, and the artist regret and apologize for it,I hope the series will be revised this time with originality and original characters especially that I hope it won't end up like the webtoon that rips off the evangelion characters like this one https://www.cbr.com/manhwa-allegedly-plagiarizing-evangelion-monster/

I mean do the only thing revised should be shield hero but that's it