They fell from the sky.
They attacked, first by using their function-specific forms to quickly travel from area to area, to attack, then changing their shape in a blink of an eye, usually into more humanoid configurations, in order to adopt an increased variety of tasks.
They pressed their assault on the world where the blazing pits of fire were visible even from the vastness of space, eager to capture the industrial capacity of this metal, near uninhabitable planet.
They attracted His Attention.
The figure in grey emerged from his palace, and regarded the grey-and-black machine.
The massive machine smirked at the much smaller humanoid that was observing him from his balcony.
"A formal surrender. I haven't had the honour of one for literally eons."
The blue-clad figure tilted his head to examine other machines waging was on His World in the distance, before looking up to directly address the invader's Leader.
"Are you all of the same race?"
"Why should I tell you, fleshbag?"
"To confirm my observations. All Machines given life by your inner core, upgrading and evolving around it."
Megatron found his hand reaching up over his spark chamber. This creature's knowledge made him a candidate for termination.
"You all alter your form between a minimum of two distinct and separate modes; logically to ultilise energy more effectively between tasks. Which suggests a priority of energy management due to constant consumption. In order to secure the resources needed for survival and operation, you engage in conquest. First on your homeworld, and when that was exhausted, you spread outward."
The undisputed leader of the invaders chuckled at the symmetry of this statement. "Power to attain power."
The creature looked Megatron dead in the optics; his eyes started to glow.
"You are misinformed. I will demonstrate what is Power."
Two eyebeams instantly stabbed Megatron where his hand had been instinctively trying to cover earlier. Any observer might find it odd that while the beams did not physically penetrate the metal body of the massive robot, the shriek of pain and bodywide electrical coruscations which were the same shade as the creature's eyebeams indicated some form of effect.
The eyebeams, while penetrating the machine, passed through it's back, turning at impossible right angles and piercing the nearest other Decepticon in the same manner.
And the next.
And the next.
Until all were one in their agony.
Darkseid of Apokolips regarded the machine in front of him.
"I have replaced your sparks with something more durable. Less prone to energy exhaustion while more ... receptive to instructions."
Darkseid smiled, regarding the symmetry of his action.
"I have given you Power. While taking it."
Darkseid regarded his new, personal army.
"Now before we discuss your next target ... it has been literally eons since I had the honour of someone swearing their blind obedience to me."
With an expression of utter despair, the massive grey-and-black machine fell to his knees before the grey figure.