I played Zentimo, then cast Crushing Hand into 2 enemy minions. I also had 2 Lesser Sapphire Spellstones in hand, uncharged.
Crushing Hand has 3 overload, and Spellstone upgrades every 3 overload. So you would think the Spellstone would charge once each, but the both became FULLY CHARGED!!! Needless to say, I went on to win that game.