Why can't I get shyvana to work in ranked (b5) but do good pretty damn in normals.

Some I'm at the bottom of the barrel in terms of rank. I've played shyvana since I started playing this game and she destroys low elo for the same reasons as yi. She may not get pentakills but she definitely fucks people's shit if if she gets ahead and she even has a gap closer unlike most bruisers. I've heard rageblade is good on her but I haven't tried it in ranked and I don't know if they still do it in Korea. My last game, I only died 1 time to the enemy and the other death was my first clear somehow. I don't know why I can't just do a full clear like I used to. You catch the enemy alone and then you kill them and take their shit. Kill dragon lvl 4 to get an early team advantage. Her biggest weakness is no cc and in turn bad ganks early. If you took ghost or exhaust, you can try to burn a flash but that's it. She can also still get kited like any other bruiser. That's why melee champions don't work in lol and DotA has the solution. It's turn time but riot won't put that I. The game since it will basically fuck with the meta. It takes time for your hero to turn but in lol, it's instant and why stutter stepping exists. What I've been noticing is I go into normals and I stomp and I go into ranked and get crushed. So is there a huge difference between even b5 and normals or am I doing something wrong.