Blackbeard : ''To the Marines, to the World Government !! And to the all Pirates out there !! (...) THIS IS MY AGE !!''''
- Manga Chapter 577
As you can see, the manga author specifically draws that Akainu is there to hear Teach's claim, and Teach doesn't afraid of Sengoku and Akainu when he challenged the entire Marineford...
And let's see why Teach ''retreats'' when he hears Akainu is coming ...
Blackbeard : ''Let them laugh ! If you're aiming for the top you don't always need your fists to show your might!!'
- Manga Chapter 225
Blackbeard makes it clear that he isn't interested in pointless battles, and sometimes you don't need to show might with your fists.
Blackbeard was doing the same thing against Ace,
Blackbeard : ''Ace had been chasing me because I committed a terrible crime aboard Whitebeard's ship.''
- Manga Chapter 544
Blackbeard was obviously not trying to fight with Ace as well despite being more powerful than him.
Blackbeard : ''How did you know I was here?!''
- Manga Chapter 440
And then his crew starts to get boring because they've waited so long.
Vasco Shot : ''We're running out of grog ! When are we going to find an island with a town ?!''
Catarina Devon : ''Right ! Forget the ship ! I need some new clothes ! I am sick of these prison rags !''
Van Auge : ''I will go take a look. They are taking too long.''
Blackbeard : ''Aye! Even they are getting impatient here !''
It's clear that Blackbeard's crew was getting impatient for waiting in that burning island.
Another interesting thing that, Akainu as a Logia user, had an environmental advantage in that location where Blackbeard waits. Akainu is a magma devil fruit's user, he would be in advantage against anyone in a ''BURNING ISLAND'' ...
San Juan Wolf : ''It's so hot !''
*Burning Island in the New World*
- Manga Chapter 595
It was hot enough to hurt someone like San Juan Wolf, who is one of the biggest living things in the world.
Crocodile as a Logia user, states that ''no one has a chance against me in a desert battle'' ... Which indicates that Logia users has an environmental advantage in time to time.
Crocodile : ''No one has a chance against me in a desert battle!''
- Manga Chapter 178
So wouldn't be the same for the likes of Ace or Akainu ? In a ''burning island'' battle ?
Let's look what Akainu turned into an island in a battle after 10 days long battle ;
''The entire place is burning''
- Manga Chapter 655
Akainu turned the half of the PH into a burning island in 10 days with using his logia powers. So in a natural burning island, Akainu as a logia user, would be in advantage against anyone, that includes Blackbeard as well.
So far, we've a confirmation about Blackbeard's challenge on every in MF battle that includes Akainu, and we've confirmation about Blackbeard's principles as a pirate which involves not fighting in pointless battles, and we've confirmation about Blackbeard's crew was getting impatient to wait in that burning island and fighting in a burning island against Akainu would be in disadvantage against a magma user Admiral.
So, why fighting in that island would be pointless ? Because Teach was trying to make a new bargain for a battleship, but they understand that they are not going to make a bargain, because of Akainu.
- Manga Chapter 595
Auge : ''I don't think it's a present for us !''
The bargain was off, they couldn't take the warship, and Akainu would use it against them in combat. So what was the point of fighting while his crew was getting impatient, in an environmental disadvantage and when they can't even get a warship ?
In short ;
- Blackbeard showed that he had no fear to challenge the entire Marine army before in Marineford battle, that includes Akainu.
- Blackbeard was trying to avoid from a confrontation with Ace as well, despite the fact he could defeat Ace with his power.
- Akainu as a Logia user, had an environmental advantage in a burning island.
- Blackbeard's crew was getting impatient to wait, they already wanted to go another island with a town even before Akainu appeared.
- Blackbeard isn't interested in pointless battles, and Teach knew that WG wasn't going to make a bargain with them for Jewelry Bonney.
Blackbeard just made a strategical retreat against Akainu.