In the Trial of the Grand Crusader, reach a Tribute Chest with at least 25 attempts remaining in 25-player mode.
A Tribute to Skill (25 player)
A Tribute to Mad Skill (25 player)
A Tribute to Insanity (25 player)
The attempts system and Tribute Chest were removed in patch 3.3.5, thus the achievement was converted to a Feat of Strength in patch 4.0.1.