After the first fight, defeat any boss without receiving damage.
Radamés definitely feels like the easiest boss to accomplish this feat with on current patch. Equipped with the Veredicto mace and "Peteneras to the Burial of the Lights" prayer, you've got plenty of damage and range at your disposal, making it fairly safe to attack him. Yerma also contributes significantly to reducing his health bar, so be certain to accept her assistance before the battle.
While the fight is simple enough to finish hitless, the key is to remain patient and avoid being overly eager to sneak attacks in, so you don't get caught by one of his charges, or take a falling boulder to the head in phase 2. You should always be prepared to wall climb at a moment's notice. Otherwise, his moves are quite predictable, slow, and easy to dodge after practicing a little. It probably won't require more than a few attempts for you to snag this trophy!
A cakewalk compared to the original game's "Requiem Aeternam" requirement, eh?
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