Trundle ult interaction with sejuani is broken
I don't know the full mechanics of it but my friend was playing sejuani and was stacking armor against the enemy team, but when he would ult her, it would reduce her armor down to -1 armor.
I believe this is because he steals her original armor so the when the passive breaks it causes her armor to be reduced drastically to nothing.
This is so very busted and should not work that way.