I have been trying out Fire tornado since 8.3 in my ignite beastmaster build for which tornado always felt quite underwhelming. Finally I decided to test the ignite and shred stacks it actually gives only to realize it actually doesn’t ignite at all so the nodes for it are useless 
Video:
https://imgur.com/a/IZDgIyV
I was actually worried about it just being poor scaling, I think if this is fixed, Fire tornado would be in a much better place.