|I think the champ design team really values readability at a glance, so if you were to find out that this magical-looking ability scaled off AD, it might be disconcerting.|
I play Shyvana and have found that building Liandry's Torment is a great option. I jump into the middle of the enemy team with W Burnout on and I shred everyone's health. While I like having this option, I think that Shyvana needs her damage streamlined so that it is more optimal to build Black Cleaver and Youmoo's Ghostblade. Right now, Shyvana doesn't have an optimal build and is struggling this season.
I suggest increasing her base attackspeed slightly and increasing the length of W without attacking to 4 seconds so she ganks better.
TDLR: Shyvana needs her W changed to Physical Damage.
I have posted about this before. Shyvana's New Hope.
Shyvana's State Season 3
CerealBoxOfDoom Shyvana Thread