The $9.3 billion merger between Endeavor-owned UFC and WWE to create a separate, publicly traded company is nearing completion, but is doing so with a perhaps murky outlook, and some big names will help guide the new entity.

The formation of TKO Group Holdings Inc. — combining WWE and UFC and majority controlled by Endeavor — is slated to be done in mid-to-late September. As deal closing approaches and both entities enjoy robust popularity among their fans, the deal carries sizable uncertainty.

Already, Endeavor CEO Ari Emanuel warned in an earnings call with analysts that “planning is underway to begin maximizing revenue and cost synergies immediately upon closing” — language that typically means layoffs.