I just noticed another bug with the rune. I ran through the Weyandt’s Revenge JP in Lions Arch wearing my set with Perplexity Runes.
When I got hit by one of the spikes in the corridor (those knocking you down), I suddenly had 5 Confusion stacks on my char. I got interrupted whilst casting my heal and therefore the effect of my 6th rune took effect – even though it should only trigger on me interrupting someone else and applying to the opponent and not me xD.
I guess the problem could be that the rune “can’t” apply confusion to an object and this case was an oversight in the fix…?
I reproduced the bug several times, casting Ether Renewal and running into one of the spikes deliberately.