This new bomb creates a ring that starts as a little ball in the center of the blast radius and quickly expands as a ring to the end of the bomb radius, then the ring shrinks back to the center.
So 1. The bomb is put down.
2. The bomb explodes.
3. A ring spreads out from the bomb explosion and then after a while the ring shrinks back to the center.
4. The ring disappears after it shrinks back to the center.
Discuss below please :)
http://forums.spiralknights.com/en/node/67425
If it's not exactly that in the OP, it's in there somewhere.