According to Billi Bhatti of DirtySheets.net, WWE is currently discussing Roman Reigns vs The Miz for the Intercontinental Title at WWE No Mercy.
If the match does indeed take place, and Reigns wins the title, he will join the ranks of Grand Slam Champions in WWE.
Additionally, WWE is currently planning a John Cena vs Samoa Joe match for No Mercy, stemming from the events which took place on Raw last week.
As of this writing, the only officially announced match for No Mercy is Brock Lesnar vs Braun Strowman for the WWE Universal Title.
WWE No Mercy takes place at The Staples Center in Los Angeles on September 24th.