When Testudo (30%/50% damage reduction) is used in conjunction with Cover (intercept all physical damage to target) the damage received by the Paladin covering is amplified by 300% to 1000% of its mitigated value - 1200-1400 damage auto attacks and 2600 ability damage.

Date & Time: December 19th, 2013 (2:00PM–7:30PM UTC)
Frequency: Always
Character Name: Brahms Torsten
Race: Hyur M
World: Gilgamesh
Class/Level: 50 Paladin
Area and Coordinates: Wolves' Den Arena
Party or Solo: Party, 4-man

Steps:
  1. I used Testudo on a low HP ally in the arena
  2. Enemy melee DPS began to attack the target with Testudo applied, I then used Cover
  3. I died in a second to the extraordinary melee damage transferred to me