Show Shyvana some love. Give her a purpose.
Shyvana is one of the champions I started the game playing and have come back to her a lot since. But one thing has always made me look elsewhere. And that is that she is part of a niche group of junglers, and top laners for that matter, that is already filled with champions that are better at doing her job than she does. At least now days anyway.
She has received a pretty sizable hit in the past couple years in the way of nerfs. But not a lot of love. Sure yes she recently got a buff that increases her damage against dragons but Warwick still kills them healthier, earlier and faster than Shyvana does and that's her entire point right now, kill dragons to become stronger.
And in the past this is exactly what she's done. Then the nerfs started, stating that they would "stop her from devouring the entire jungle". First was her base attack, sure it was a little high but still lower than most. Then you nerfed her Burnout, made it give less movement speed and do less damage her only aoe ability. Thankfully it was still usable and could be compensated with AP like from gunblade or nashors. But then they got rid of the AP scaling.
Next was her E. I guess it was going top much damage so you lowered the base strength and the scaling. Then after a while you raised the scaling back up which was nice thanks.
Then her ultimate was hit, the damage lowered quite a bit but added in the whole size upgrading thing and added the unstoppable feature. Which was cool. Although I'm fairly certain her ultimate E slowed at one point then that was taken out and I'm not sure why.
As for her place in the game she really doesn't have one. She doesn't fill a particular niche that other champions don't fill better. Like Master Yi and Warwick for example. She doesn't have any survivability unless you count her ultimate with is also her only engage tool. And even if she has killed five dragons that's only 25 points of resistances, and the possibility that she can even accomplish that when surrounded by better junglers is dubious at best, especially at higher tiers of play. Not to mention that the other half of her passive isn't even useful during 85% of the game.
My recommendation is that you either replace her W with another ability, like maybe a roar. I've never seen a dragon summon a circle of fire around them, and at this point it's nothing more than pretty colors with the lack of any damage it does, but I've seen lots of dragons roar. Or if you want to keep the current theme of Burnout you could make it cause a small explosion of flame around her point of origin that inflicts those around it with magic damage DOT and blasts her forward in a short dash, maybe leaving a short line of burning earth along the path. In her dragon form maybe this ability is slightly larger with a larger range depending on the ults rank, maybe add a small knockup. Idk but do something with it, it's hardly even useful in clearing the jungle.
