"Deflecting attacks will become easier to execute thanks to a wider window for button input."
— Inventory description
Like all the other unlockables, Easy Deflect will be put in the Item Box on subsequent playthroughs and refreshes in the Item Box should it be discarded from the player's inventory at any given time. Easy Deflect has to be in Chris's inventory for it to function.
Easy Deflect increases Chris's ability to deflect enemy attacks.