Icon

Obtaining
The Icon will appear in your Inventory upon drawing the Sword from the statue at start of a playthrough, provided Mormo was defeated in the previous run.

Use
The Icon is used as a sacrifice to the Ruins at night. Doing so will trigger monsters to appear as it usually would. After killing them, one of the five lights around the platform will light up.

Do this 5 times (this requires multiple playthroughs) and defeat Mormo for a surprise! (If you lose a fight however, or if you can't kill them in time, you will lose the icon FOR GOOD! Be careful when offering.