It was pretty good

Thanks!
Alright, since Zab already addressed it, I'm going to explain it in a way everyone can understand.
I've already gone over how Yoru possesses the power of the gun, its power level and how it works. See here:
A weapon’s strength created by Yoru or Asa is
directly based on how guilty they feel about turning someone into a weapon. Asa, due to her deeper emotional ties and guilt,
has created stronger weapons than Yoru. However, in this case, Yoru forged a weapon out of
28% of her child,
the Gun Devil, which formed a gauntlet on her right arm. This gauntlet was described as
more fearsome than any of Asa’s weapons.
Now I'll explain how Makima obtains the Gun Devil's ability.
Yoru for sure got her powers from gun, but what is the exact evidence that Makima did too?
Let’s go over the basics. As the Control Devil, Makima has shown the ability to
control any life-form she perceives as lesser than herself. This control is not limited to
humans, it extends to
devils,
fiends, and
animals alike. After taking control, she can also use the abilities of those under her influence,
whether they are alive or deceased,
even if the abilities originate from devils they had contracts with.
Makima’s profile also notes that her powers are passive and extend to everyone she meets, and even to those she controls posthumously. This suggests that she may possess the powers of devils she has never directly encountered or controlled. This is supported by her eventual control of the Zombie Devil, which she
only discovered after Denji had killed it, yet it later appears
among her controlled minions.
Now, with that in mind, we also know that when facing opponents she cannot or chooses not to immediately control, she will engage them in battle until she proves herself superior to them.
From this we can conclude:
- Makima’s control is passive.
- When she is uncertain whether she is superior to her opponent, she will engage them in combat.
- Once she takes control of a devil, she can use that devil’s abilities as her own, even after their death.
Now, after Makima defeated the Gun Devil in their 12 second showdown, according to her plan, she took control of it and forced it into Aki’s corpse, compelling it to fight Denji. The key point here is that Makima clearly took control of the Gun Devil, meaning she gained access to its abilities.
We also know that Makima has the ability to control anything, which allowed her to cultivate the Gun Devil’s power as her own,
even altering its size and potency.
With all these context clues and implications, as Zabzab said Chainsaw Man rarely ever confirms things outright. But in this case, the clues are clear and straightforward.