I FINALLY DID IT! DIAMOND WITH SHYV TOP
With a little help from my first ever Aegis of Valor, (holy shit the euphoria made me lightheaded) I managed to claw my way to diamond playing only Shyvana top. I have 2.2 Million mastery and I am convinced that Shyv top is more than viable, I'm a little biased and would say she is even S tier.
I used to use a google spreadsheet of shyvana top matchups that was posted here but it got taken down, both the post and the spreadsheet, so I was forced to improvise. Instead of improvising, I mostly just stuck to the default Triforce, Shojin, DD and Steraks build with Grasp, but I did change my runes depending on matchup. As Citric once said switching up your build too often is not good, you really need to stick to one or maybe two builds and really get to know your damage and capabilities (or something like that, I can't remember his exact verbiage).
https://op.gg/lol/summoners/na/Ryguy101-6969
EDIT: The guy finally approved my request for access to the spreadsheet! Only now I don't need it, hopefully it can help you guys: https://docs.google.com/spreadsheets/d/13P7UI0l1hOUBqmLQyiOu7nMf-cZ6jmm7il_2H39-EsY/edit?gid=0#gid=0