How to Get Radagon Icon - Elden Ring 

Travel to the Debate Parlor of Grace at the Academy of Raya Lucaria.

As you exit the Debate Parlor site of Grace, turn right.

Continue up the ladder after jumping over the railing onto a platform.

Look to the right and you will see a broken window, once you reach the top of the ladder.

Jump through the window and go right. You will see a chest.

In the chest, you will find the Radagon icon.

Radagon Icon is an accessory that reduces spell casting time.

This is very useful for any class that uses spells, especially when in combat.

The shorter spell cast time gives them more time to cast more spells.