Dragon Quest VIII: One Turn, Over 20,000 Damage to a Single Foe
Today, I finally achieved over 20,000 damage to an enemy--over twice the HP of the Ultimate Dragon--in one turn. I also beat the previous record (link at bottom) by about 250 points of damage.
As you can see, the reason so much damage was recorded was that the same Troll was brought back to life and struck down again. Even though it died, the new damage was still added to the total. I used Pink Typhoon because it has a damage cap of 400, making it the easiest way to damage a Troll (about 400 HP) without killing it.
Even more damage would be possible if Angelo could get a turn in to cast Divine Intervention on the Troll after it was brought back, so that Yangus could do up to 11,999 damage with Typhoeus' Maul. Unfortunately, my Angelo is too fast, and always goes before the Dark Moths.
Hero and Yangus had attack powers of 999 and 721, respectively.
Previously largest known damage (20183):
http://hapi.cc/dq/dq8_maxdamage.html
The Dragovian equipment is from beating the Dragovian Trials.