In the latest we find out that Xebec killed an Admiral at Marijoa during a reverie.
The only other known character in the story that has every taken down(defeated in this case) an Admiral was of course Akainu, who defeated former Admiral Kuzan.
However I do want to point out the difference between Xebec killing Admiral, and Akainu defeating an Admiral.
When it comes to Xebec vs the unknown Admiral, we still don't know the full story, how it went down, or anything like that.
But we do know that Xebec killed the unknown Admiral at Marijoa, why is that important? Because it pretty much means, that the unknown Admiral was nerfed during his confrontation with Xebec.
And no, for any mindless clowns out there, that are saying he wasn't nerfed, read the manga again, because it was stated during the Sabo Reverie flashback, that the Admirals are nerfed at the Holy Land.
As for Akainu defeating Kuzan, that battle took place in Punk Hazard, where both characters went all out, in a ten day battle.
They were not nerfed, and they did not need to hold back.
Regardless, Xebec and Akainu are again the only two characters in the story that has either killed or defeated an Admiral.
But what other characters like Pirate King himself or the Yonko's?
None of them has ever killed or defeated an Admiral, heck none of them even defeated anyone notable.
Let's go down the list.
Roger: The Pirate King himself, failed to defeat Garp and most likely failed to defeat Sengoku, never defeated Whitebeard, and needed Garp's help against Xebec.
Kaido: Mr. Rumor man himself, the one that his fans put as top 1. When it comes to Kaido, he needed the help of his crew to defeat Moria and his crew, he never defeated Hanafuda, he was almost defeated/killed by Oden, and he needed Higurashi's help in order to get a fraud win over Oden.
Big Mom: I'm not even going to bother with her.
Whitebeard: The World's Strongest Man! Who never defeated Roger, and most likely never defeated anyone else notable.
So yeah when it comes to the Pirate King himself and the Yonko's, none of these guys defeated anyone super notable including an Admiral.
And remember defeating an Admiral is a huge deal, these guys are the strongest fighting power of the World Government.
There is a reason why there are only three Admirals.
For all we know, Xebec was probably the first person in a very long time, to actually take down an Admiral, something that wasn't seen again until with Akainu vs Kuzan.
The killing of the Admiral, made Xebec the most wanted man in the world, got a huge bounty, made the World Government super angry, and because of the killing, is most likely the main reason on how he got characters like Whitebeard, Shiki, Big Mom, and others to join him.
Meanwhile when you have two Yonko's like Kaido and Big Mom being defeated, yeah it made news but other than that, it was overshadowed by other news such as the whole Sabo incident.
The World Government were a bit upset at first, but they quickly got over it and easily replaced Kaido and Big Mom with Luffy and Buggy as the new Yonko's.
To me it's obvious that the killing of an Admiral is a much more bigger deal than the defeat/killing of a Yonko.
One last thing I will say about Xebec, this guy should not be grouped with the Yonko's, man killed an Admiral, had Big Mom, World's Strongest Man, Mr. Rumor Man, and Shiki all as his subordinates, and it took both Roger and Garp together to fight against him in a 1v2.
Random Tags:
@Kurozumi Wiwi @Sentinel @Elder Lee Hung @Tyki_Mikk @RayanOO @EmperorKinyagi @Uncle Van @kekaro @soupongo @MarineHQ @AkainuTheGrimReaper @SakazukiTheFist @RyoQ @Mr. Reloaded @Roo @ZenZu @Owl Ki @Blackbeard @Dragon777 @Doggo @TheKnightOfTheSea @DarkestKnightofSpoilers @SDfear

The only other known character in the story that has every taken down(defeated in this case) an Admiral was of course Akainu, who defeated former Admiral Kuzan.


However I do want to point out the difference between Xebec killing Admiral, and Akainu defeating an Admiral.
When it comes to Xebec vs the unknown Admiral, we still don't know the full story, how it went down, or anything like that.
But we do know that Xebec killed the unknown Admiral at Marijoa, why is that important? Because it pretty much means, that the unknown Admiral was nerfed during his confrontation with Xebec.
And no, for any mindless clowns out there, that are saying he wasn't nerfed, read the manga again, because it was stated during the Sabo Reverie flashback, that the Admirals are nerfed at the Holy Land.

As for Akainu defeating Kuzan, that battle took place in Punk Hazard, where both characters went all out, in a ten day battle.
They were not nerfed, and they did not need to hold back.
Regardless, Xebec and Akainu are again the only two characters in the story that has either killed or defeated an Admiral.
But what other characters like Pirate King himself or the Yonko's?
None of them has ever killed or defeated an Admiral, heck none of them even defeated anyone notable.
Let's go down the list.
Roger: The Pirate King himself, failed to defeat Garp and most likely failed to defeat Sengoku, never defeated Whitebeard, and needed Garp's help against Xebec.
Kaido: Mr. Rumor man himself, the one that his fans put as top 1. When it comes to Kaido, he needed the help of his crew to defeat Moria and his crew, he never defeated Hanafuda, he was almost defeated/killed by Oden, and he needed Higurashi's help in order to get a fraud win over Oden.
Big Mom: I'm not even going to bother with her.
Whitebeard: The World's Strongest Man! Who never defeated Roger, and most likely never defeated anyone else notable.
So yeah when it comes to the Pirate King himself and the Yonko's, none of these guys defeated anyone super notable including an Admiral.
And remember defeating an Admiral is a huge deal, these guys are the strongest fighting power of the World Government.
There is a reason why there are only three Admirals.

For all we know, Xebec was probably the first person in a very long time, to actually take down an Admiral, something that wasn't seen again until with Akainu vs Kuzan.
The killing of the Admiral, made Xebec the most wanted man in the world, got a huge bounty, made the World Government super angry, and because of the killing, is most likely the main reason on how he got characters like Whitebeard, Shiki, Big Mom, and others to join him.
Meanwhile when you have two Yonko's like Kaido and Big Mom being defeated, yeah it made news but other than that, it was overshadowed by other news such as the whole Sabo incident.
The World Government were a bit upset at first, but they quickly got over it and easily replaced Kaido and Big Mom with Luffy and Buggy as the new Yonko's.
To me it's obvious that the killing of an Admiral is a much more bigger deal than the defeat/killing of a Yonko.
One last thing I will say about Xebec, this guy should not be grouped with the Yonko's, man killed an Admiral, had Big Mom, World's Strongest Man, Mr. Rumor Man, and Shiki all as his subordinates, and it took both Roger and Garp together to fight against him in a 1v2.
Random Tags:
@Kurozumi Wiwi @Sentinel @Elder Lee Hung @Tyki_Mikk @RayanOO @EmperorKinyagi @Uncle Van @kekaro @soupongo @MarineHQ @AkainuTheGrimReaper @SakazukiTheFist @RyoQ @Mr. Reloaded @Roo @ZenZu @Owl Ki @Blackbeard @Dragon777 @Doggo @TheKnightOfTheSea @DarkestKnightofSpoilers @SDfear