I'm just curious what's the best way to hide magma Like almost invisible

You can't. Just use a massive rose and rotate it accordingly until it can't be seen properly. The hurtbox goes way farther than the mesh of the rose itself.

If you really need magma then the only way to "hide" it is by shoving it into another block, and boom it's hidden! The magma's hurtbox extends slightly further than the block itself, so that's why that works. Just beware of z-fighting if you're doing that.

OK I just don't know where roses are

Decoration tab.

You COULD use the rose method, but it's very difficult to use. I for one would try doing something with the portals, similar to the Turkey Trials 1950's Level.