Star power and the status quo are more likely to dethrone Bryan than his current masked challenger. Lesnar is a transcendent star, and Cena is WWE's go-to champ. They are the threats hovering most closely around Bryan's gold with hungry hands.
Bryan and his fanbase also have to worry about Bryan's critics ignoring visual and auditory cues and pushing for an alternative.
Lesnar would be among the top choices to push Bryan out. Armed with name recognition and a proven championship pedigree, he is Bryan's biggest obstacle to a long, uninterrupted reign.
The Beast Incarnate
Before Lesnar famously defeated The Undertaker at WrestleMania 30, he was barking about getting a title shot. He named himself No. 1 contender, and only challenging The Deadman distracted him from his title pursuit.
With WrestleMania out of the way, it is inevitable that Lesnar comes after Bryan at some point.
His high profile puts him in line for a title shot despite his part-time status. He's a valuable commodity to place in the main event. Besides, WWE is reportedly discussing having him take Bryan on once August rolls around.
According to Wrestling Observer Newsletter, via Marc Middleton of Wrestling Inc:
Brock Lesnar is not booked for the WWE Extreme Rules pay-per-view and likely won't be back until SummerSlam. There's been speculation that he may challenge Daniel Bryan for the WWE World Heavyweight Title.
Bryan fans shouldn't fret just yet, though. There is also word of Lesnar taking on Cesaro at SummerSlam, per Wrestling Observer Newsletter, via Nick Paglino of Wrestle Zone.
Lesnar, though, offers the threat of an advantage in star power. Bryan may eventually grow into the kind of star that Lesnar is, but for now, the bigger man is a bigger name.
As The Rock swooped in and took the spotlight and the WWE title from CM Punk in 2013, Lesnar could do the same against Bryan.
It seems that doubters don't stop doubting, even when proven wrong.
The story of Bryan's ride to the championship centered around Triple H and Stephanie McMahon not believing him worthy of the title due to his size and a perceived lack of a larger-than-life persona. It's a narrative that many assumed was born from reality.
A recent report points to that being true and that for some, the lack of support for Bryan didn't go away after a magical WrestleMania.
PWInsider, via Middleton of Wrestling Inc, reports, "Some higher-ups feel that Bryan isn't over, it's the 'yes!' chant that is over. They feel that Bryan peaked at WrestleMania XXX with the WWE World Heavyweight Title win."
This is the kind of rumor that sounds too insane to be true. Wrestlers who connect with the audience as deeply as Bryan has over the past two years are extremely rare. This isn't Fandangoing, where the fun of a song is the star and not the performer himself.
What are the chances Fandango is going to get a "You deserve it!" chant?
If there is indeed a group of WWE officials still discrediting what Bryan can do, there's certainly a chance that these folks would push for another champion.
If ratings slip with Bryan as champ, he is sure to be the scapegoat. It's often wise to wait to see if low ratings are anomalies or regularities, but WWE can often get trigger happy with naming a new champion to turn things around.
Should WWE get antsy in that way, there is one wristband-wearing wrestler whom WWE would first turn to—Cena.
Leader of the Cenation
Cena wearing the WWE title is as common a sight as a dog wearing a collar.
WWE World Championship history says he will be champion again. Since first winning the title in 2005, there have been only two years, 2008 and 2012, where he wasn't WWE champ. The company is clearly most comfortable with him on top, and Bryan will have a difficult time unseating him from the throne.
Even looking to the future, WWE has Cena pegged as one if its pillars.
As reported by Wrestling Observer Newsletter, via Middleton of Wrestling Inc, "WWE, right now, is looking at the top four singles babyfaces for down the line to be John Cena, Daniel Bryan, Cesaro and Sheamus." It seems that no set of up-and-comers is going to push Cena down from the marquee.
There is also past history between Cena and Bryan to tap into. It was Bryan who ended Cena's reign as the WWE titleholder. As he did against The Rock, Cena could be the center of a story of redemption and proving himself.
There would be great interest in a Bryan vs. Cena rematch, one that could well result in Cena earning his 12th WWE title.
For now, though, it seems that WWE is content with having Cena battle emerging stars as a way to build new names for the future. He's been entangled with Bray Wyatt for months, bringing added spotlight to The Eater of Worlds.
In addition, according to F4WOnline, via Mike Killam of Wrestle Zone, "Cena would like to work a program with Big E at some point this year."
That collision, and his long feud with Wyatt, could keep Cena busy and the WWE title out of reach. Unless Bryan becomes as marketable a Superstar as Cena and proves that he attracts casual fans at the same rate, he will always have the threat of the long-time king coming back to take the crown.