In the Avengers: Endgame. These were the movies that fully introduced the audience Thanos, a villain who had only made cameos up until that point.
However, as incredible and breathtaking as these movies were, they were not a flawless depiction of the character of Thanos. Like any movie's characters, there are some things that just don't fully connected about Thanos and fans are still struggling to make sense of it all.
Loving Gamora
When Thanos seeks acquisition of the Soul Stone, Red Skull instructs him that he must sacrifice that which he loves to obtain it. This leads to a sequence where Thanos tearfully hurls Gamora, his "daughter," over the cliff to obtain the next stone.
From his warped perspective, he believes he does love Gamora. But he's such a sociopath that it seems hard to make sense of why he would actually, truly care for her. If someone is willing to end someone's life for a rock, do they truly love that person? It seems like Thanos doesn't have that capacity.
Trusting Servants
In hindsight, MCU fans learned that Loki invaded Earth in The Avengers because he was on a mission of culling from Thanos. It's not a bad plan, but when it backfires, there are some questions to be raised about Thanos' steps going forward.
For example, why does he continue to trust people like Gamora, Nebula, and Ronan to acquire stones and divide populations for him? At a certain point, Thanos should have realized that he could only trust himself, but he never does. He even inexplicably dispatches more aliens in Infinity War.
Relying On Knowhere
In Infinity War, to entice Gamora to come to him and reveal where the Soul Stone is located, Thanos hangs out on Knowhere and uses the Reality Stone to create an illusion with The Collector. It's a plan that relies on too many variables that could go wrong.
For example, what if Thor had successfully convinced the Guardians to avoid Thanos and plan to kill him instead? Then, he'd have never had access to Gamora. It's a plan that works for him, but it makes no sense why he'd rely on it so heavily.
Using The Stones
Thanos' use of the stones varies from scene to scene. In one, he's using them to break apart an entire moon and hurtle it at the Avengers fighting him on Titan. In another scene he's holding back and allowing himself to duel with the superheroes.
If Thanos can use the stones to destroy a moon, he can probably use the stones to decimate his competition. If he's so hellbent on seeing his plan through to completion, it makes no sense why he would toy with the heroes instead of quickly getting them out of the way.
Letting Tony Live
Speaking of his extended interactions with the superheroes, it's a bit unclear why Thanos feels the need to let Tony Stark live after bartering a deal with Doctor Strange. When he threw a moon at him, he was content to see him perish. So why the change of heart?
Some say that Thanos doesn't want to cause any more death than he has to, but when he snaps his fingers, Tony might die anyway. Between saving Tony and merely punching the heroes in Wakanda, Thanos' commitment to his intentions are highly obfuscated.
Connection To Stark
Before he spares Tony Stark's life, though, Thanos engages in a bit of interesting dialogue. His fight with Iron Man is underscored by his use of Tony's name. For Stark, he's stopped a bit as he wonders how Thanos knows his name, but he ignores it to fight the Mad Titan instead.
But Tony raises an interesting point. How does Thanos know Tony? He probably has been briefed on the Avengers team that foiled his New York invasion, but Tony is the only one he ever acknowledges as a worthy foe. His connection to him is a bit odd.
His Plan
One of the biggest things of Thanos that makes no sense is his plan in the first place. His goal is to collect the Infinity Stones to snap half the universe's population out of existence to ward off a breaking point for all living things.
But if the stones can do anything, can't he just make a breaking point impossible? Can't he just expand the universe? The fact that Thanos thinks of murder immediately is an aspect of his plan that is utter nonsense. He's just too blinded to see it.
Thanos' Endgame Army
When Thanos learns of the Avengers' plan in Endgame, he uses a past version of Nebula to acquire Pym Particles so that he may also return to the present timeline and fight the army of superheroes aiming to undo his work.
However, his army is the part that makes no sense. If this scene unfolds in a matter of seconds, how does Thanos rally an entire army onto his ship and then shrink them down in time to fight the heroes? It's incredibly quick work that doesn't immediately line up.
He Doesn't Actually Do It Himself
In the post-credits scene of Avengers: Age of Ultron, Thanos slides his big, purple hand into an Infinity Gauntlet and remarks, "Fine. I'll do it myself." There is so much that makes no sense about this.
For one, he clearly doesn't do it by himself, as aliens like Ebony Maw are dispatched to obtain Infinity Stones for him in Infinity War, which occurs three years after Ultron. Furthermore, the scene implies that Ultron was one of his minions, but this is also never explored.
Pick A Gauntlet, Any Gauntlet
The biggest aspect of this scene that makes no sense, though, is the Infinity Gauntlet itself. The post-credits scene implies that Thanos obtains the Gauntlet for the first time in 2015.
However, Infinity War states that he forced Eitri the Dwarf to forge him an Infinity Gauntlet. He did not obtain it from some secret vault. Coupling this with the odd Gauntlet in Odin's vault and it's extremely unclear which Gauntlet is real and which one isn't.
