When Ari, co-CEO of mega-agency WME/IMG — and a man known for his high-profile fights with half of Hollywood — demurred, Lashinsky prodded: “I thought you embraced risk.”

Said Ari: “That’s not risk. That’s pure reward.”

In an opening day filled with surprises at this year’s Brainstorm, perhaps the biggest surprise in tonight’s headliner event was that there wasn’t more blood—and swearing (Only one bit of profanity was uttered).

That said, there was plenty of sparring. When Ari — whose WME (William Morris Endeavor) acquired IMG, a giant in sports, media, and fashion representation, in a $2.4 billion deal last year — outlined the exhaustive range of businesses his company was now in, big brother Rahm was visibly impressed. “That’s because I’m the younger brother,” Ari said, “and he never thought I could do anything.”

“Don’t use the past tense,” said Rahm.

WME/IMG is now the world’s dominant player in entertainment, sports and fashion representation, and an emerging powerhouse in event staging, the gaming business—and, as Brainstorm participants learned this evening, bullriding as well.

The mogul, who is reputed to be the inspiration for brash and hyperkinetic agent Ari Gold on the HBO series “Entourage,” said he’s intent on moving the company more toward the “ownership of assets” and less to representation. When WME made the IMG acquisition a little more than a year ago, roughly 70% of the company’s revenues came from representation, with the remaining share coming from owning various businesses. It’s now closer to 60:40, said Ari.

Rahm’s dealmaking has been harder going, it seems. The mayor, who won a hard-fought reelection a few months ago, is in the midst of a bruising battle with the city’s teachers union (and wrestling a breathtaking sum of pension obligations) to stem Chicago’s deep financial crisis.

Hizzoner said none of those harsh realities was going to stop him from his top priorities—of which education has clearly been paramount. “When I ran for mayor, Chicago had the shortest school day in the country: five and a half hours,” said Rahm. Kids got out at 2:40 in the afternoon. “If that was so great, I want to know why Beijing didn’t come and copy it.”

During his first term, his administration added an hour and fifteen minutes to every day, he said, as well as two weeks to the school year.

That prompted a moment of unexpected brotherly praise: “He’s not afraid to take on a challenge,” said Ari. “He always is coming up with new ideas.

When asked what Zeke, an oncologist, renowned bioethicist, and the oldest of the Brothers Emanuel, would have added to the conversation were he there, Rahm and Ari were united again: Said Ari, “He wouldn’t get a word in edgewise.”