Originally Posted by mikebro

The effect doesn't remain unless this was changed recently. At least, the bonus AP is removed from the warrior when he removes the trinket. I'm not sure if it removes it from the rest of the party. My plan was to battleshout in arenas with the Sapphire equipped during the 1 minute preperation period, then switch to a more beneficial trinket right before that gates opened. Didn't work, though.