Everybody's twins

As the battle progressed, the Avengers that were still trapped under the collapsed building finally managed to get out and save themselves while fighting the Chitauri Army that was swarming the area. Meanwhile, Nebula also met herself again and her sister Gamora at the same time. 

The traitor Nebula finally got killed by her sister, Gamora! But the good news was that the Infinity Stones were finally on the Avenger's hand once again. Nebula failed to hand the Infinity Stones back to Thanos before she met her demise.

Vision also regrouped with Natasha and helped her escape to the surface smoothly. 

Then everyone finally saw Dio, Steve, and Thor sharing the Mjolnir, knocking down Thanos continuously. But it didn't mean that the danger was completely alleviated! The Avengers didn't know about their own incoming reinforcement, but neither did Thanos! Even so, Thanos still changed his strategy and let Dio hit him with Mjolnir to dodge Thor's Stormbreaker!

Thor's Stormbreaker still hit Thanos but missed Thanos' vital spot. The Stormbreaker still pierced through Thanos' armor and carved a huge gaping wound on his waist. However, Thanos had his reason for letting Thor's attack through! 

Thanos seized the moment and immediately attacked Steve, who was wide open in front of him, with his huge twin blade! 

Steve knew that he couldn't do anything to prevent Thanos from attacking, so he gritted his teeth and raised his shield to block Thanos' attack with everything he got. Thanos's twin blade immediately split Steve's shield in two, rendering it useless. Thanos attacked once again as he wanted to reduce his enemy.

Steve knew he could no longer defend himself now that his shield had been destroyed. In the face of this critical situation, Dio threw Mjolnir toward Steve so that he had something to protect himself, and at the same time, Dio raised [Reaper's Gaze] and swung it at Thanos' neck. 

If Thanos really wanted to kill Steve right now, then it would become his end too! Even if Dio had to sacrifice Steve's life for it, he would never lose to Thanos again! But he knew that Thanos wouldn't be so reckless that he'd choose to kill his enemy over staying alive! 

At the same time, Thor rushed towards Steve, trying to help Steve stop Thanos' attack with his Stormbreaker. 

But Thanos smirked as he saw what Thor was planning to do. He changed his twin blade's course and struck Mjolnir, that was still flying in the air, to hit Thor. The force of Mjolnir that hit Thor's back forced him to let go of his grip on the Stormbreaker and knocked him to a wall along with Steve, who stood right behind Thor. 

That was not all! Thanos then twisted his body, dodging Dio's scythe, and changed the trajectory of his twin blade to stab Dio in the chest! 

The enemy that Thanos wanted to kill from the beginning wasn't Steve, but it was Dio all along! 

"You are finished!" Thanos said with a big smirk on his face. 

Dio was surprised, but he didn't panic! He knew that he couldn't dodge Thanos' attack, but he could still do something! He activated [White Album]'s Gently Weeps ability, instantly reducing the temperature of the area to nearly absolute zero! Everything in the vicinity was instantly covered with frost, and even the air began to freeze! 

Thanos was inevitably affected as he was only around a meter away from Dio. Thanos' attack became extremely slow and stiff due to the freezing effect of the frost! The twin blade that had pierced [White Album] a little bit couldn't move any further as Thanos has lost his momentum to frost! 

Nevertheless, Dio wasn't affected by his own Stand's power. 

Even so, Dio himself couldn't move! He felt his entire body going stiff without any explanation, and he couldn't even move the [Reaper's Gaze] that was already on Thanos' neck. Suddenly, a voice was heard from behind that quickly explained everything.

"Master! Nebula has been killed, but our soldier is ready to proceed with the next plan." Ebony Maw came to the scene with countless Chitauri behind him, raring to mow down the Earth at Thanos' command.

Thanos shattered the frost that froze him and looked at Dio coldly. He raised his twin blade and swung it at Dio, but fortunately for Dio, something struck Ebony Maw in the air, knocking him to the ground, which cancelled his telekinetic power on Dio, allowing Dio to move once again. 

Nevertheless, Thanos' attack hit Dio hard! Dio received a huge wound in his abdomen, and it could end up disastrous if he didn't treat it as soon as possible! But Dio also counter-attacked at the same time, creating a big gaping wound on Thanos's shoulder.

Dio turned his attention towards Ebony Maw realised saw that the thing that knocked the telepath down was Mjolnir! He looked around and noticed that the one who threw the Mjolnir to knock Ebony Maw down was Natasha! 

It was shocking as Dio never knew Natasha was worthy to wield Mjolnir, too! Even Thor was shocked as he saw who threw his prestigious hammer! Apparently, he found out that everyone could wield Mjolnir now! 

Unfortunately for everyone, Thor had to return Mjolnir back to the past once this battle was over! 

But still, Thor was pretty irritated that he wasn't as special as he thought! He couldn't keep Mjolnir for himself as his own Mjolnir had been destroyed by Hela, and he also knew that he had to send Mjolnir back in time as it was his responsibility to preserve the timeline. 

This was why Thor just looked at Mjolnir longingly as he knew that Mjolnir would never be his again. Even though he knew Mjolnir was still technically his weapon even after he sent it back to the past, his current self wouldn't have it anymore! 

So, it didn't matter if the others could wield it now, as Mjolnir was just a weapon of the past!