Rune of Decimation

I got the RA Rune of Decimation.
I have read about it on camelotherald.com, this is the description in there:

What i get out from that text is this:

You place the RoD on the ground, and everytime someone enters it in a pulse, BAM insane damage.

But this is not for me. When someone enters it, it does damage and then it goes away. Should it disappear after being used once, or is my RoD bugged?

It is supposed to disappear.

Read:

It's supposed to be a gimped overpriced RA.

Once someone have entered the radius it will blow of and dissapare.. just like a mine. But it will stay on the ground for 8 mins if no one steps on it..