Lol no. The Other is the only Other version of Kang we'll see because Kang killed off all the other doubles during his time travel and this one became the body of the being known as Chthon accidentally during the dawn of time. Who represents aspects of black magic and the dark matter side of physical existence. He accidentally became Mandarin's ancestor but this wouldn't be revealed until it's revealed he has been shepherding the timeline like Beyonder, and was running across time from beings from beyond time that want to see the universe destroyed. Would very much like to see Thanos do that.
He travels time too and looks for powerful leaders, kings, conquerors and Titans, as well other powerful entities to try to aid his cause which is the destruction of all matter... he's anti-matter, dark matter, spaces in between connected to the dark world, dark magic, and prophecy. basically he looks for powerful villains to make more villainous.
When he speaks to Loki on the astral plane that is going on within Yggdrasil, through the roots of the world tree. On the inside. Within Loki's mind. The Other version of him influences people from any time period, any space, and dragged Loki out of that black hole... and returned him to the universe, forcing him to serve a being he had never met from very far away.
The "space" scene where Loki talks to the Other is actually going on within Loki's head which is why it looks like his head hurts after, and The Other is very powerful ancient being who can only work through people or with people...
In theory it could possess a weaker mind, but can only interface with stronger minds and meet them on astral planes, one of Chthons abilities the Other gained when it travelled to the dawn of time and fractured Kang. Which caused a split in the realm of black magic and alerts Strange and Ian Mcnee.
And Thanos may not be a main villain in Avengers 2. And in GoTG more of an anti-hero working against the church of universal truth for half of GoTG before he betrays the team, and they find out he was using them to eliminate Magus when Warlock returns from a time pocket.
Thanos will most likely still be a part of phase 3.
This is what Feige had to say, I'm jumping ahead too much--the key would be everything, many of the subplots, culminating in phase 3, and many things not being revealed until things culminate in later films. "Part of a bigger world, they just don't know it yet" and may not find out about things, although many things will be planted along the way:
“There’s a great track record now about lobbing something in at the last moment to get the audience buzzing[...] Particularly when it came to Thanos, [we knew] that most people in that audience had no idea who that purple guy was — but they could clearly tell he was important, and knew if they asked the two or three people sitting next to them, somebody would know who he was.
“Clearly, there’s a purpose to us putting him in the end of that movie. We do have plans for him[...] I wouldn’t say we ever feel the need to rush anything one way or the other. We succeeded in Phase One because we stuck to our guns and stuck to the plan. That plan took place over many, many years and it ultimately paid off. I see Phase Two unfolding in the same way of us taking our time, us doing what’s right for each individual movie, while folding in elements that will not only build up to the culmination of Phase Two, but even Phase Three.”
I'm working from the standpoint that there are some overall plans and things could go a few different ways and certain key parts have been put in place. While other things change or get shuffled forward like Wasp and the villain Whedon was talking about who wasn't Nebula but Nebula was supposed to be there with Thanos until the other came into the plan...
The Other has to be someone from the comics and has some sort of abilities that kind of hint at what he is. But Chthon is a red herring for those who may know the character and the Other name serves a dual purpose. His demonic appearance takes shape over time.
The Other also has to be important, he can't just be some random for them to have replaced Nebula with him very, very early on after the Zak Penn script was tossed. And Nebula will now show up in GoTG with the church and Magus or Korvac i believe, working both sides as she's really serving Thanos right now.