The Blackstone Inc. executive who shaped the identity of many of the private equity giant’s companies is spinning out his entire team to start a brand agency.

Blackstone’s Jonny Bauer, who has led its brand strategy group, will debut FundamentalCo early next year as a 12-person shop. Fashion designer and television personality Jenna Lyons, J.Crew’s former president, will join as the firm’s executive creative director.