The source of the entire 1981 Research Institute's pollution is that Mechanical Heart.
Normally, attempting a direct assault would likely never be capable of killing it.
But the timing chosen by Leonard Churchill and Seven Brown was just right.
They had the advantages of a weakened state and the Hot Melt Knife.
Moreover, the Mechanical Heart couldn't move. As long as they could get close, they could make a hit.
The key to killing it was the layer of Alloy Armor on the outside of the Titan Heart.
If the defense couldn't be broken, then even in a weakened state, it was nearly impossible to kill this creature.
As for the Hot Melt Knife, since the will of the Space made it only so long, it was certainly capable of piercing through that Alloy Armor.
Moreover, Leonard Churchill had previously observed the structure of the heart when he descended and had already analyzed the possible weaknesses of this monster to Seven Brown.
As anticipated, one strike was deadly.