A born leader always had power, even if it was in someone else's hands for a day or two.
Megatron may have been "hired" by TRF to take out the remaining Autobot scum but he was no follower. He made it his goal to remind the humans, Lennox especially; he had total control over every action and consequence that was bestowed upon them.
Will was the only human who opposed him. At times, the warlord wondered whether this was a serious challenge of authority or simple stupidity.
Every time the human failed to heed his commands, he felt the desire to put Lennox in his place. He wanted to show him how much power he had over the life of the Lieutenant Colonel. There was, of course, the problem of size for many of the examples he wished to attempt but even that didn't stop the tyrant from performing hegemony.
Will Lennox still stood too proud for his own good, not bowing to the warlord no matter how much the mech displayed his supremacy. The human even had the gull to trash talk him in front of his warriors and the government officials with their trigger-happy subordinates. He never seemed to learn but interestingly enough that was what made him such fun for Megatron to take on.
They were well aware of each other's purposes, both of which became rather disoriented over the course of a week. But Megatron had nothing to stand down for which was why the warlord stood victorious among their quarrels despite Lennox never actually submitting to him.
A simple leverage of power and control got Megatron exactly what he wanted and more. When Lennox stepped out of line, he was just as quick to remind him of his now permanent place among the Decepticon Crew. He made his intentions very clear but even when that supremacy was outright, he still found himself praising Lennox's brash behavior. Will dared the tyrant to play his bastardly game in public which was considered a bold move for someone so small.
It eventually led to a darker stage of their relationship. Power play seemed to do nothing but have them give into their primal egos. It was what they loved and hated about each other.
AN: Well, I may have put sexual tension in there somewhere. I figured this is where I start implying the relationship since that was the goal, was it not? Naughty stuff may come later. IDFK!