ok, I downloaded "Slightly flavored" 1.21 and interestingly, way stones was included and worked without issue. I took a look, and the most recent version of it released was for 1.20, so I think it gave that version priority over the 1.21 version. I was curious, and looked into mahou Tsukai, and saw it had the same thing on its page. though when I tried manually installing the 1.21 versions, it still crashed on loading. I'm not sure why Waystones wasnt working previously, but I guess that issue is fixed, so its fine. I don't know why mahou is labeled as 1.21 if it crashes every time, but thats an issue with the mod creator then. I'll just have to wait for a new release