Whats with the octagon?

Question

From time to time I see a MASSIVE (at least 800 range diameter) blue octagon (or hexagon, it's gone too quick to be sure) on champions. It's gone in about 2-3 seconds everytime, too quickly for me to screenshot it by the time I realize it's there. I'll keep trying though.

Further details: It's not a perfect shape, it has runes or mini shapes within it, some look like triangles, almost as if its several shape's outlines stacked on top of each other at different axi.

Whats with this thing? Has anyone else seen it?

Answer 1

What you are looking at is most likely the particle effect for the active of the Shard of True Ice. This is the only image I could find on the Internet, but I believe the particle effect gets more detailed.

The active effect for the Shard of True Ice slows all enemies near your (allied) target by 30%. This effect lasts for 4 seconds. Common targets include tanks/initiators (to keep enemy teams from disengaging) and carries (to keep them alive if your team disengaging).

The Shard of True Ice builds out of a Kage's Lucky Pick, Mana Manipulator, and 535 gold.