The thread was lost in the forum purge from a couple years ago. The basic set up was a Rock-type Deoxys-A (Skill Swap Color Change) with Pure Power (Skill Swap again) at +6 Attack that gets a Choice Band (easiest to do with Trick). This gives the level 1 Pokemon 108 Attack. Looking at it now, Marowak would be the better choice in reality, but NetBattle had a bugged damage formula. Marowak could get 112 attack, so as long as it has the right moves it can work, too.
The target is a level 100 Ho-oh. I could pick something like Delibird, but Ho-oh seems more interesting. =) Ho-oh has at minimum 322 HP and 41 Defense.
Marowak's attack is Rollout, which you will have to be clever about to use. You need to use Mimic to learn Assist, then Assist Defense Curl, then Assist Rollout. Deoxys-A has it easier, since it can Mimic Rollout and Snatch Defense Curl. The 5th turn has a base power of 1920.
That gives you about 3x overkill on Ho-oh without a CH.