How to impress a teacher so you can get a PH D despite bad qualifications?
Science isn't about groundbreaking discovery, those are sci-fi movies.

Real science is about boring consistency. You don't need to solve the Riemann hypothesis, you need to demonstrate you can churn out a few good enough papers a year with minimal supervision. Include some funding proposals in there, bam MVP :)

Unfortunately for you, grades are a reasonable proxy measure for boring consistency.  The reasoning being: good grades imply that you can understand new content and have the discipline to put the hours to get a decent grade doing boring work unrelated to your interests. So you would need to demonstrate with papers, which is significantly harder (and takes a while), and this idea will backfire if the papers aren't good enough...