Jon Peterson put up an excerpt of a letter by Gary Gygax with Mordenkainen's stats.
Me, I went right past the stats to he has a Staff of Power with 192 charges. Well, had, he used 12, so he's down to a mere 180. Yowza.
Okay, okay, I know that staves in white-box D&D can have 200 charges. But coming to OD&D from AD&D, it really jumped out at me seeing it on a character sheet. And the Staff of Power is no slouch of an item, it dramatically increased the effective firepower of a magic-user.
The damage of it doing a retributive strike is god-smitingly powerful, based on Gods, Demigods, & Heroes, too . . .