i remember there was this thing where sages wall would randomly turn green and break easily, but i had no idea what caused it. does anybody have any idea? ive always seen it but never actually figured it out.

Is my crosshair accurate? I'm new, bad at aiming and want to be sure it's 100% a skill issue. As you can see at the end, some I get right and others I blow it when it's right in front of me. I want to make sure I'm practicing the right way...