Use Gem Box + Economizer and use Quick on someone with Genji Glove and Offering (I used Sabin). They'll die
Actually, Quick only works on the person casting it, so that scenario would be impractical. If somebody with a Gem Box and Economizer casts Quick on themselves, it's impossible for them to also have the Genji Glove and Offering. And if somebody has the Genji Glove and Offering, then they would have to spend all 99 MP to cast Quick.

And Umaro works best with a Gauntlet instead of his Blizzard Orb. His attacks are only against one enemy at a time, but they are much more powerful. Just go into the menu to look at the stats, you'll see what I mean.