Tom Hiddleton's Loki is arguably the greatest of the Marvel Cinematic Universe villains so far and we believe he needs to die. In the next two years the main story threading the 22-movie franchise crafted by Marvel Studios is coming to an end, and with it, potentially several important characters.Phase 3, as it has become known as, concludes with what was originally announced as a two-part Avengers: Infinity War saga, with two additional films (Ant-Man and the Wasp and Captain Marvel) debuting in between. The third and fourth Avengers movies eventually became two separate stories, mostly shot separately as well due to massive scheduling needs for the record-setting ensembles.Related: Thanos Can't Be Just Another Boring Marvel VillainThey both however will feature Earth's Mightiest and their cosmic allies (the Guardians of the Galaxy) fighting Thanos and attempting to undo whatever damage he's done with the Infinity Gauntlet. In that respect, when it's all said and done, the conclusion of Avengers 4 may partially reset the story or at least lay a foundation for a new and different start.This is the biggest story Marvel Studios will have ever told and it will feature real stakes this time. It needs to. Heroes will die. Villains will die too.

Loki Needs to Die to Justify Thanos

If there's one criticism that can be applied to the MCU as a whole it is its lack of worthy villains. Marvel Studios boss Kevin Feige has said in the past it is by design to focus on the heroes and fun of that, but there's no denying that several films have suffered from a lack of development of its antagonists. Inexplicable villain plans or an absence of justifiable motivations can't last forever and this is why we're starting to see characters that are more morally grey and no longer one-and-done villains.

The Winter Soldier (Sebastian Stan) served as a Terminator-esque unstoppable force in the second Captain America film and is now a fan-fave hero. Doctor Strange's mentor Mordo (Chiwetel Ejiofor) was setup in that origin film as a future antagonist, but one who isn't truly evil, but rather, has justifiable reasons to do what he's doing. The same can be said for Zemo (Daniel Bruhl) in Captain America: Civil War and we suspect, next year for Black Panther's Erik Killmonger (Michael B. Jordan).

Some of these newer villains, like Loki, could have long-term arcs in the future of the MCU, sometimes even teaming up with heroes for bigger, more evil threats.

It's this villain problem though that is the biggest challenge the MCU must conquer in concluding Phase 3 and building the finale around Thanos, the purple Mad Titan who's only been briefly teased over the last few years via cameos in post-credits scenes (in Avengers 1 and 2) and in a few sparse scenes in the first Guardians of the Galaxy.

Related: About That Last Infinity Stone¦

When we visited the set of Guardians of the Galaxy Vol. 2 early in 2016 Feige told us that Avengers: Infinity War is virtually a Thanos movie. He's the star. He gets a lot of screen time because he needs it for the obvious story reasons of collecting the Infinity Stones, but also to justify himself as the greatest and most deadly villain. When Thanos is introduced on screen, for real this time, he needs to make his mark and makeup for his past failures. We think he's going to do that early in the film in a big way.

Here's how...

Thanos wears the Infinity Gauntlet in Avengers Infinity War

Thanos is A Killer From The Start

In the Avengers: Infinity War teaser trailer, which earned a milestone-setting 230 million views in its first day, we see Thanos (Josh Brolin) with the Infinity Gauntlet having its first stone already in it. The first stone he collects is the purple-colored Power Stone which we last saw in storage at Nova Corps HQ on the planet Xandar featured heavily in 2014's Guardians of the Galaxy. That means he goes there, likely wipes them out, and then heads to Earth.

The second stone he gets is the blue Space Stone, which resides within the Tesseract. We see Loki handling the Tesseract to a taller figure in the trailer, in the midst of destruction, essentially confirming that Loki does indeed nab this cosmic cube at the end of Thor: Ragnarok before Asgard is destroyed.

Thanos is coming to collect and Loki is in debt. If you recall the first Avengers movie, it was Thanos who provided the scepter and Mind Stone to Loki, along with a weak sauce Chitauri army to "invade" Earth, and collect the Tesseract. Loki of course failed, lost the scepter, and Thor took Loki and the Tesseract back to Asgard (but inexplicably left the scepter). That meant Thanos had zero stones instead of two. That meant Thanos failed as a strategist making his first introduction in the MCU a rather weak one.

Not to be outdone, Thanos couldn't get the job done two years later either when it came to the purple Power Stone when he mistakenly hired Ronan the Accuser (Lee Pace) to collect it in the first Guardians of the Galaxy. Notice the theme here of Thanos failing. Over and over. Big bad master strategist Thanos seems like an idiot, and one who was talked down to by Ronan. Ronan even killed Thanos' servant and Thanos did nothing. Not impressive as the deadliest Avengers villain, right?

So how does Marvel make up for that and re-position Thanos as a legitimate foe?

Have him quickly and effectively do what he does best: kill everything. Have him wipe out Xandar (kickstarting the reason the Guardians get involved) and provide a future need for a new Nova Corps like the comics (insert need for Nova spinoff in Phase 4!) and then when Thanos confronts the surviving Asgardians from Thor: Ragnarok, he can take them out too, get the Tesseract from Loki, and kill him.

Thanos does not forgive. He should kill Loki. And if this can happen in the first act of Avengers: Infinity War, audiences will know Thanos means business and can take him seriously.

New Marvel Cinematic Universe Needs New Villains

By the end of the untitled Avengers 4 in 2019, Phase 3 will conclude and along with it, the entire 22-set of films forming the Marvel Cinematic Universe. There are many films with many heroes coming after it (and now, potentially the X-Men and Fantastic Four!) of course, but these three phases will end the franchise in its current form.

That means, for story and contractual reasons, it's possible none of the original six Avengers will star in their own films as leads after Avengers 4. It means that along with sequels for the newer characters (Doctor Strange, Black Panther, Captain Marvel, etc.) and all-new properties (including cosmic spinoffs of Guardians of the Galaxy), new and more meaningful villains will need to take the spotlight. Some of them have already been introduced or will be soon. But just like we suspect a few Avengers will be gone in 2019, so to should Loki.

His arc is complete. Loki was a villain, sometimes a hero. He faked his death once already, got the throne, and even helped Asgard as it fell. There's little more he can do as a cinematic villain. Bye bye, God of Mischief.

More: Avengers: Infinity War Rumors We Like/Dislike

Share your thoughts and theories, hopes and desires for Avengers 3 and 4, and let us know what you want to see in Phase 4 in the comments!

For more: CBR, Marvel

Key Release Dates