Michael Bay's five Transformers films are loud, full of explosions, and packed to the brim with robot-on-robot action. So, they're the perfect summer blockbusters! Less than perfect, however, is the Autobot leader, Optimus Prime. Optimus has spent countless eons fighting Megatron and his brood of Decepticons across the galaxy and it seems that this endless conflict has turned the once noble Autobot leader into a hardened and quite frankly hyper-violent soldier bent on destroying his enemies at all costs. Legendary voice actor and voice of Prime, Peter Cullen, has even stated in interviews how he's struggled to make sure the films stay true to the character as the franchise marches forward into darker territory.

RELATED: Why Optimus Prime Is Evil in Transformers: The Last Knight

This year's Transformers: The Last Knight seems to be following that arc to its logical conclusion by turning Optimus Prime himself into an enemy of humanity and of his former Autobot allies. This isn't the first time Optimus has come across as less than what CBR likes to call "good." In fact, a lot of what Optimus does and believes seems pretty evil. Or at least borderline "not very nice." The dude's downright brutal on the battlefield but regardless of what Prime needs to do to get the job done in a fight, many of his decisions and actions within Bay's films show that Optimus can be just as horrible as his Decepticon foes and at times, much worse.

15 BRUTALLY EXECUTES PRISONERS

Throughout Michael Bay's film series, Optimus Prime waxes poetic about how he and the Autobots fight for peace, justice, and for the greater good of all humanity on Earth. However, the endless war against Megatron and the Decepticons seems to have caused the mighty Autobot leader to lose perspective. Actually, Optimus seems to have become quite bloodthirsty. His defeated Decepticon foes, even when they beg for mercy, still suffer his violent wrath.

In 2011's Dark of the Moon, Optimus ignores both Megatron and Sentinel Prime's pleas and brutally murders them after they are soundly defeated. Taking prisoners clearly isn't an Autobot policy. In Revenge of the Fallen, Optimus helps the U.S. government track down and dispatch all Decepticon fugitives, even blowing Demolisher's brains out after he's incapacitated.

14 ENDANGERS CHILDREN

This one is the most obvious example of Optimus Prime's increasingly graying moral spectrum. Not only does the ancient Cybertronian War spill out onto the streets of countless cities across the Earth, but it also drags teenagers into the center of conflict at every turn like Devastator's metal-grinding tornado of a mouth.

All the children hapless enough to be in the vicinity of Optimus Prime during the films are violently sucked into the Transformers' battles and used like chess pieces in their never-ending fight for victory on the planet. Sam Witwicky is the scariest example as everything he touches seems to be a long-lost coveted Transformer relic. Because of Optimus' failure to secure the Allspark in the first film, the Decepticons kidnap and try to lobotomize Sam -- not to mention the fact that he has to avoid assassination attempts in between horrific battles. As if starting college wasn't stressful enough.

13 ABANDONS EARTH

Optimus' creed of "freedom is the right of all sentient beings" becomes "see ya later" in Dark of the Moon when he gives in to the Decepticons' demands to leave Earth. Although it was a ruse, what a profoundly risky gamble to make!

First, why did Optimus think it was wise to play things so close to his truck-sized chest? Shouldn't maybe a few key allies be privy to the big Autobot counterattack? Like, perhaps Sam? Good job, Prime. Now your closest friend thinks the Autobots are a bunch of cowards who have abandoned humanity. Instead, Optimus is alright with sending the humans barreling into Chicago, hopelessly outmatched and outgunned, and without any knowledge of his plan in order to do what? Maybe soften up the bad guys a little? Clearly, Optimus' judgement is seriously lacking by Dark of the Moon.

12 BETRAYS HUMANITY

In Michael Bay's latest and last entry in the Transformers film series, The Last Knight, Optimus Prime returns to Earth after some soul searching around the galaxy -- only to have a change of heart and become an enemy of all humanity and really of organic life itself. This "Nemesis" Prime proceeds to set his sights on his former Autobot allies as well, beating the grease out of Bumblebee,\ and slicing countless other bots in half over and over again.

And which big, horrifying, planet-eating threat does this only slightly more evil than regular Optimus Prime lure to the planet this time because of his shenanigans? Why, it's Unicron! The Lord of Chaos! The Chaos Bringer! The Planet Eater! That's right, Unicron. He eats -- universes!  Your bad, Optimus. And you're bad.

11 LURES DECEPTICONS TO EARTH

In Transformers, Optimus has the bright idea to start broadcasting a signal to all Autobots around the galaxy in order to gather his buddies on Earth. However, this of course also draws other Transformers to the planet -- namely countless waves of murderous Decepticons! The mere presence of the Autobots on Earth becomes a dangerous lightening rod for not only Megatron and his cronies, but for rogue elements like the ruthless bounty hunter Lockdown.

And each Decepticon invasion force is larger than the last! Optimus's "good intentions" turns Earth into the latest battlefield for the Cybertronian blood feud between the two factions. Optimus Prime doesn't seem to understand that the Autobots can't hide on Earth as robots in disguise and shoot out a mass text to the entire universe about the intergalactic kegger they're starting in our solar system.

10 DESTROYS CYBERTRON

In Dark of the Moon, Sentinel Prime and Megatron strike a secret deal to use a space bridge to bring Cybertron to the solar system and enslave humanity to revive their long dead world.

Under Optimus Prime's leadership, the Autobots never think twice about destroying the Pillars creating the space bridge as it's transporting Cybertron to Earth's orbit -- thereby obliterating their entire home world, forcing the Autobots to remain on the planet, and dooming humanity to endless Transformer-related conflict for the undetermined future. Optimus is clearly an "any means necessary" sort of leader and is dangerously short-sighted. Diplomacy, consequences -- these are things Optimus fails to consider. Instead, he's totally okay with Cybertron's destruction. And helping to wreck Chicago. Again.

9 MURDERS EVERYONE

"Give me your face!" quips Optimus hungrily just before he rips the Fallen's metal skin from his skull in the final battle against the Decepticons in Revenge of the Fallen. When Optimus isn't slicing helpless and disarmed enemies apart with blades, he's ripping the Sparks out of chests with glee, skewering faces with razor sharp hooks, and tearing robo-necks and spines out while screaming his new favorite catch phrase: "I'll kill you!"

Optimus Prime is a warrior who revels in battle. A soldier hardened by countless years of galaxy-spanning conflict -- but the hero of the Transformers films is actually only interested in fighting and subsequently, killing. Megatron is more willing to open up negotiations for a truce in the third film than Optimus is. Megatron!

8 FILLS EARTH WITH FUGITIVES

Besides drawing every Decepticon in the universe to Earth, Optimus also fills our planet with Autobots who wish to hide from said Decepticons...and eventually causes them to hide from the U.S. military and government when diplomatic relations break down.

By the time of the events of 2014's Age of Extinction, all Autobots have been declared enemies of humanity unbeknownst to the public and are hunted down by CIA black ops teams. Honestly, this turn makes a lot of sense within the canon of the films. All Optimus Prime has brought to Earth is war, death, and destruction. Humanity is clearly not better off giving the Transformers asylum and Optimus' refusal to leave the planet just puts more humans in danger due to the battles fought against the Cemetery Wind in Age of Extinction.

7 USED BY THE U.S. GOVERNMENT

The U.S. government begins experimenting on Transformers technology thanks to the their presence on Earth. Utilizing Seeds to create "transformium," the U.S. creates drones based on the Cybertronians such as Galvatron and Stinger. A new fight breaks out in Age of Extinction as the human-made Transformers are used to hunt down and destroy the remaining Autobots and Optimus Prime.

Also, it is revealed that Megatron somehow transferred his consciousness into spark-less Galvatron's body and goes rogue, which causes further chaos and destruction amidst the rest of the chaos and destruction. In the end, what has Optimus' interference on Earth left humanity with? Only the creation of new, highly advanced, and violently terrible weapons of war. Side note: Megatron has now died and been reborn twice in the series.

6 WON'T SHARE TRANSFORMERS HISTORY

Optimus probably doesn't know every secret of Cybertron's past but in Michael Bay's films he seems to either know next to nothing -- or has refused to share any pertinent information with the other Autobots and their human allies. One of the more consistent expositional failures has to do with never telling anyone that the Transformers have visited Earth in the past -- many, many times in the past.  In Transformers, Optimus fails to tell anyone that their greatest enemy, Megatron, has been frozen on Earth for thousands of years just waiting to be thawed out after failing to acquire the Allspark. Surely Optimus must have known that his predecessor, Sentinel Prime, had previously crash landed on Earth's moon? Not to mention that it's revealed in The Last Knight that Transformers fought alongside King Arthur in medieval Britain.

5 CAUSES THE DEATH OF HIS FRIENDS

Optimus Prime's leadership not only puts his friends in danger, but gets them killed as well. Both his human and Decepticon enemies aim for Optimus but usually hit his allies in an attempt to take out the Autobot leader. In Dark of the Moon after Sentinel Prime reveals that he's made a secret pact with Megatron and the Decepticons to sacrifice Earth in order to revive Cybertron, he betrays the Autobots by blowing Ironhide's brains out. Ironhide, the second most interesting character in the entire film series.

Poor medical bot Ratchet is murdered in Age of Extinction by the vicious intergalactic bounty hunter, Lockdown, when he refuses to reveal Optimus' whereabouts. Where was Optimus when Ratchet takes the fall? Why, he's hiding out in Mexico City. Yes, the Autobots are at war but Optimus decision to run and hide from Lockdown and the U.S. government is downright cowardly. His soldiers shouldn't be taking the fall for Optimus' failure of leadership.

4 BLINDED BY OLD HATREDS

As previously mentioned, Optimus Prime isn't really the go-to bot when people need a little diplomacy to solve their problems. In fact, diplomacy never seems to be an option. The only time Optimus ever negotiates something with the Decepticons was just so that he could enact an elaborate ruse in Dark of the Moon.

Optimus is as much to blame for perpetuating conflict as his Decepticon enemies. At least Megatron was willing to form a temporary truce when things got a little out of hand with Sentinel Prime's plan in the third film! Mercilessly executing prisoners, a dogged and unflinching black and white worldview, and an inability to learn from the mistakes of war -- these are the actions of a leader who is blinded by old hatreds.

3 COOL WITH TORTURE

Let's face it, the Transformers of Michael Bay's films are some pretty violent autonomous sentient robots. They're hardened warriors clinging onto whatever they can in order to get by. Arguably the Optimus of the movies crosses some lines that the classic Prime in other media wouldn't. However, after being captured in IDW's Transformers #22, Megatron pushes Optimus Prime to go down a path the Autobot leader never thought he could.

Optimus tortures Megatron with a "voltage harnass," raising the device's intensity to the point that it could kill his long-time enemy. Only due to timely and concerned interference from the other Autobots does Optimus cease his torturing of the Decepticon, clearly driven over the edge from both Megatron's goading and a desperate lifetime of nonstop fighting and war.

2 ENSLAVES THE DINOBOTS

Outmatched and outgunned in Age of Extinction, Optimus Prime decides to call in some reinforcements -- by forcibly recruiting the Dinobots (Grimlock, Scorn, Slug, and Strafe) to the Autobot cause. By defeating Grimlock in battle, Optimus then subjugates the Dinobots into service. It's not like Prime gives the fire-breathing mechanical T-Rex a choice, stating: "You defend my family...or die."

Perhaps strength is the only thing the primitive Transformers understand but if that's the case then they certainly do not understand war or how Optimus only wants to use the Dinobots to crush his enemies. The Dinobots are clearly only more expendable fodder for Optimus' endless war against the Decepticons. The Dinobots are definitely not more free under Optimus' control than when they were prisoners of Lockdown.

1 OBSESSED WITH DESTROYING THE DECEPTICONS

Optimus Prime claims to fight for truth, justice, and freedom for all sentient beings but fails to recognize that he is just as unflinching in his own belief system as Megatron and the Decepticons are in theirs. His actions demonstrate that he'd rather hunt down and destroy every single Decepticon rather than open any sort of dialogue between the two factions. Safeguarding Earth and saving human lives is far less crucial than killing Decepticons or possessing powerful Cybertronian relics.

Optimus Prime in Michael Bay's films not only enjoys fighting Decepticons, he even relishes in slaughtering them. Mercy, understanding, love -- these are not the Autobot ways and not the ways of Optimus Prime. Only when the Decepticons lie dead at Optimus Prime's feet will the carnage finally cease.

Transformers: The Last Knight is currently in theaters everywhere.