PORTALS

Imagine the movie stays the way it's, but the ultimate battle is different... The battle up until the portal’s scene remains the identical. After the portals scene they include more clips of character team ups, 1v1s between an Avenger and a Black Order, and just more action normally. Then, as they desperately attempt to keep the stones removed from Thanos while his ship is firing down on them, some stones become separated from the gauntlet; thanks to the chaos and destruction, some of them fall to the bottom. Thanos gets a hold of the space stone, power stone, reality stone, and mind stone. Meanwhile the heroes have the soul stone, and also the mind stone is nowhere to be found...?! Thanos uses their powers to achieve a plus within the battle, he does some cool things, etc., but after some minutes the heroes ultimately overcome and kill him... but then, in a very slow fashion, the whole tone of the scene and soundtrack shifts to something very eerie, confusing and scary. The heroes begin to urge flashbacks to the darkest moments of their lives; the mind stone is causing this. The heroes begin to listen to Thanos' voice speak to them, despite his body lying within the battle field. they appear around to work out his entire army vanish before their eyes. they're confused and frightened; That's when Tony, who has the soul stone, begins to steer forward as if he's bringing the stone somewhere. Thanos' voice continues to talk to them as they're halfway during this reality, halfway experiencing their darkest moments from the past. Everything becomes disorienting and trippy. Reality is questionable. Thanos' "dead" body vanishes, and also the entire look of the environment around them shifts... the full place is now covered in a very mountain of thousands of dead bodies and skeletons. Tony begins to steer to the highest. As he approaches the height, we see Thanos sitting up there on a pile of skulls kind of like the magazine. His armour is repaired, his blade is new again, and he's alive and well - and he's using the fact stone; when the heroes thought they won, it had been just a cloaked reality that Thanos was having fun with. He had already won. Now he just needs two more stones, so using the fact stone he's forcing Tony to bring him the soul stone. The soundtrack is spooky and shady, creepy and startling. The build-up to the present moment lasts a pair minutes; a pair minutes of flashbacks, darkness, disorienting and confusing reality. the whole time Thanos was chatting with them about how he had already won, that this was all a game to him. Tony turns around to work out the Avengers at the underside mostly dead or dying, kind of like his vision in Age of Ultron. rather than Cap saying, "you could've saved us," Thanos says, "You should've saved them, but you didn't. When I'm done only, you'll be what's left of humanity - and that I hope you remember them." As Tony is near to hand him the soul stone, something happens using the time stone and Doctor Strange to forestall this. Time freezes and Doctor Strange incorporates a chance to clarify his plan - everything from why certain choices were made, why he offered the time stone in 2018 on the planet Titan, and wherefor he let Starlord hit Thanos, etc. Also, he clarifies that when he offered the stone to Thanos, he had perturbed it for this moment in 2023. He knew that 2018 Thanos had already used the fact stone and mind stone to send his 2018 consciousness to his past 2014 self, just case he were to die, so he'd have his past self as a backup plan that will know everything, including what to try and do come the ultimate battle. it had been all inevitable - the snap, the try and undo the snap, and this big battle. it had been also unavoidable that Thanos would AGAIN get his hands on the stones because he's just too strong, especially together with his entire army. So, the tip of Strange's plan was to curse the time stone to interrupt the fact stone's spell, consequentially undoing Thanos' guaranteed win. that's a part of the 1 in 14 million. Time unfreezes, and once the fact stone's spell is broken, the fact stone breaks down and temporarily dies, leaving Thanos with the ability, space, and mind stones. Additionally, Thanos is weakened and confused by this initially, allowing the heroes once last shot. This a part of the battle would focus round the remaining original Avengers - Iron Man, Cap, Hulk, Thor and Hawkeye, all fighting Thanos, until Tony gets his hands on the remaining stones and snaps, rather like he does already.
I know this is not the foremost organized or well thought out idea. Basically, I envisioned an extended final battle that also includes the stones toward the tip. My favourite a part of Infinity War was the fact stone scene. Mind-blowing. I'm picturing that again but much shadier, lengthier, and scarier, as if "wow, this can be it! Thanos had an idea and has earnt..." then again it's exposed that Strange also had a plan. Time stone trumps reality stone's power during this case. I visualize this to be a daunting scene, fairly. I comprehend that this idea has both stones performing some hardcore feats, but that is what the infinity war is all about, right?
The Russo's were once questioned if throwing the moon and creating  part was Thanos' peak, or if there was more to coming back; their reply was "The best is yet to arise." I admit I had some brutal big ideas of what to assume for end-game and was a little bit more hopeful.

Here is my take on an alternative ending of end-game.