Sakon and Ukon's bodies had not merged.
Instead, they remained split in two as they fought Kankuro's two puppets.
Sakon and Ukon's method of attack was simple indeed.
However, his powerful regenerative ability made him exceptionally difficult to deal with.
Unless someone used ninjutsu that exceeded the limits of Sakon and Ukon's regenerative ability to forcibly obliterate him.
Otherwise, he could keep fighting until he wore his enemy down to death.
Kankuro was a puppet master, and controlling two puppets in battle at once made him no less troublesome than Sakon and Ukon.
However, he had no ninjutsu or ninja tools with tremendous destructive power.
Thus, he could only remain locked in a battle of attrition with Sakon and Ukon, neither able to overcome the other.
Sakon and Ukon's Secret Technique: Parasitic Demon Demolition Technique only worked when it struck a living body.
Its essence was to break down his own bodily tissue and infiltrate the enemy's body, devouring the chakra within and destroying their network of channels, rendering them unable to move.
That was how Kiba Inuzuka and Akamaru had lost their ability to fight.
However, puppets were not living beings, so the "parasitic" secret technique could not be used on them.
And to approach Kankuro's body, Sakon and Ukon first had to destroy the two puppets.
Unfortunately, the bodies of Kankuro's specially crafted puppets were terrifyingly sturdy.
Even after exhausting every means at his disposal, Sakon and Ukon could not forcibly tear either one apart.
The hovering puppet, in particular, had suffered no damage even when his body had swollen and exploded earlier.
Its resilience was all the more astonishing.
Sakon and Ukon could do nothing about the two puppets.
And Kankuro had no ninjutsu capable of forcibly obliterating Sakon and Ukon, so the two could only continue