The inaugural WWE World Heavyweight Champion Seth Rollins is scheduled to defend his title for the first time on RAW next week on Monday. The Visionary became the inaugural WWE World Heavyweight Champion at Night of Champions last Saturday when he defeated AJ Styles.
The title was introduced last month by WWE Legend Triple H as an alternate World title. Roman Reigns had been carrying both WWE Championship and the Universal Championship since WrestleMania 38 and he was not defending his title regularly either. For example, it’s been two months since WrestleMania 39 ended, and Roman Reigns did not defend his title even once since.

Opponent Revealed: Seth Rollins To Defend His World Heavyweight Title On RAW
It might have been good for Roman Reigns but certainly not good for the rest of the roster. They needed more main eventers that can only be built if there is another World title and it was defended regularly. That was the biggest reason why the World Heavyweight Championship was introduced.
The World Heavyweight title was just won at Night of Champions and it would now be defended next week on RAW. WWE has already announced this on their official site and the opponent is the former WWE United States Champion Damian Priest who is a member of the Judgment Day faction. WWE wrote on their site;

Seth Rollins Is Scheduled To Face Damian Priest Next Monday On RAW
“The World Heavyweight Championship will be on the line when Seth “Freakin” Rollins defends the title for the very first time and it will be against none other than The Judgment Day’s Damian Priest. Rollins issued an open challenge on social media daring any Superstar to step up to the challenge and Priest answered it, much to the delight of the champion.”
Damian Priest is a pretty random opponent. They tried to add a backstory of the online open challenge but it was a random match which is pretty clear. Surely, by this random challenge, they are trying to prove that the World Heavyweight title would be defended regularly and anyone is able to challenge for it.

WWE is yet to build a steady feud for the World Heavyweight title yet but as of it stands, it looks like Finn Balor is going to be the first legit opponent that Seth Rollins is going to have. There are still big rumours of a heel Drew McIntyre challenging Seth Rollins for the title. Hopefully, the World Heavyweight title picture improves soon.