As of the DBS: Broly movie, if Beerus were no longer the God of Destruction of Universe 7, and the next GoD for U7 is a mortal from U7, then are four potential candidates: Goku, Vegeta, Frieza and Broly.
Vegeta has seemingly been queued up to be Lord Beerus' replacement as the new God of Destruction, but Beerus' real successor is actually Lord Frieza.
Beerus, the God of Destruction from Universe 7, is the one who sealed Old Kai in the Z Sword. His administrative zone includes planet Earth. Each God of Destruction has an Angel attendant, like Whis for Beerus and Vados for Champa.
15 Will Surpass: Goku May Have Already Surpassed Beerus
Literally referred to as the "State of the Gods," it would be no surprise if Ultra Instinct Goku could already beat Beerus. As the main character, Goku eventually surpassing Beerus is all but guaranteed.
His Hakai Ki is able to amplify his power yet again and become even stronger than before, however in the manga it is repeatedly stated that Vegito blue is stronger. Vegito blue has a power level of 10.8 Septillion, therefore Beerus most likely has a power level of 10.7 Septillion.
That said, it really does seem like Zeno will stay the strongest god in Dragon Ball for the foreseeable future. His level of power is so incomprehensible that it seems highly unlikely Goku will ever fight Zeno, let alone beat him.
Although Jiren is said to be able to defeat a God of Destruction, it's unlikely Beerus is at risk of suffering that defeat. Beerus has yet to use 100% of his powers in Dragon Ball Super thus far, whereas Jiren at 100% struggled against Mastered Ultra Instinct (MUI) Goku.
Whis is one of the strongest beings in existence, and interestingly enough, only his father and the Omni King are confirmed to be stronger than him.
Belmod is the God of Destruction of Universe 11.
The God of Destruction of Universe 10 is Rumsshi, the Supreme Kai is Gowasu, and the Angel is Kusu.
Freeza himself though? No, even if he won on earth, he'd never surpass Beerus. His great potential is one thing, but it has a cap. Freeza couldn't even be bothered to actually master his golden form, so if he did that, you can bet he wouldn't be able to figure out how to surpass the next wall.
Beerus, the God of Destruction (Japanese: 破壊神ビルス, Hepburn: Hakaishin Birusu) is a fictional character in the Dragon Ball franchise created by Akira Toriyama.
Lord Luud was Dragon Ball's First God of Destruction, Not Lord Beerus. The Luud Cult is an organization that worships Lord Luud–an entity that is only described as being an all-powerful “God of Destruction” as that exact description is said multiple times by a number of Lord Luud's disciples.
According to the Battle of Gods animanga, Beerus was based on Toriyama's cat, which is a Cornish Rex. The Cornish Rex breed has no fur, except for down, which a fine undercoat of fur (most cat breeds have three layers of fur) that gives them a nearly hairless appearance.
"Future" Trunks Saga
Shin explained that due to the death of Future Beerus, Future Whis is rendered inactive until a new God of Destruction is appointed. Along with the other Angels, Future Whis died when the timeline was erased by Future Zeno.
According to Toyotaro, not only does Whis have the ability to use Ultra Instinct, but is constantly using it at all times without having to undergo any transformations, showing why the angel has been a force to be reckoned with, whenever he does decide to fight.
That question was actually answered in the story. Whis said that if Beerus died, his duty as a guide angel would be suspended until there was a new God of Destruction. When a God of Destruction dies, the angel who attends to that god becomes inactive until a new god is chosen.
Being trained by Beerus in the ways of Destruction Energy, Ultra Ego Vegeta would presumably be nearly equal to him. While Beerus likely still wins the fight, Vegeta is probably the closest mortal to actually being on similar ground with Beerus.
Frieza cannot expect to defeat a God of Destruction who can casually destroy halves of planets on the tap of his fingernail. Plot armor had always affected Beerus' strength, and it's probably not a great idea to buff Frieza so much that he can casually go toe-to-toe against the likes of Beerus.
But without Ultra Instinct, Jiren still has the advantage over Goku. In order to defeat Jiren, Goku had to team up with both Frieza and Android 17. On his own, the only hope Goku has of defeating Jiren is by fully mastering Ultra Instinct, and being able to activate it at will.
Did you know Broly can surpass Goku after training? Depending on the circumstances, Broly has a unique ability. to tap into the power of the berserk Super Saiyan, also believed to be the real. legendary Super Saiyan in the past, and this power. gives him immense strength and durability.
Vegeta has surpassed Goku by learning techniques his rival could not, but the Saiyan Prince hates that his new abilities are "parlor tricks." Warning: contains spoilers for Dragon Ball Super chapter 73!
Super Saiyan 3 Goku at full power has a battle power of 24,000,000,000, 2 billion above Kid Buu's level.