Gear: T5 Bracers, World Boss Cloak, Arena INT necklace, rest T4 (CON less DPS dagger and Talisman)
AA: Pressig Strikes, Decisive Strikes, Will of the Sublime, Chilling Breath, Decays of Nature
Set's Cold Hatred
No potion buffs of any sort except Moonspill, no use of Tome of Epithur
No spell weaving
Strawman: The one from the Veteran Rewards vendor, which expires after 3 minutes.
Several Runs with the
With Withered Soul and Unholy Inspiration build from above with four Arcanists. Haven't had the time to test the other one yet. Each run over the three minutes I did around 280k damage, with natural variance.
Then several runs with the
Despoil the Soul build. The best one did 246k damage over these three minutes.
Both numbers should be reproducible by everyone. If someone under these conditions manages to reach significantly higher numbers with the same gear and a Despoil the Soul build, I really would want to learn how he did it. No irony, no sarcasm.