In Thanos: The Infinity Siblings GN Kang the time-travelling Conqueror saw a future even-more-powerful Thanos defeated by something that went on to ravage the multiverse. He went back in time to recruit Thanos' brother Eros, Pip the Troll and current Thanos himself in a plan to stop that future happening. They succeeded but in fact current Thanos had been taken control of by future-Thanos to ensure *his* future happened. And Eros sneakily copied Kang's time-tech because he thought it might come in useful some time.
In Thanos: The Infinity Conflict GN the controlled Thanos kept killing Adam Warlock every time he regenerated. Meanwhile Eros and Pip used time-travel and teleportation to try to kill Thanos. Meanwhile again the Living Tribunal (who since Thanos: The Infinity Finale has been another version of Adam) told Adam to kill Eros as the only way to stop future-T. He did so but Eros was rejected by Death rendering him like Adam and Thanos, 'existing outside the norm', which was LT's plan. But in the future Thanos absorbed all the cosmic beings in the multiverse including LT, thus becoming omnipotent.
Now read on ...
We start with repeating a scene from the end of Conflict. Thanos has absorbed Death and all the other cosmic entities and now faces the Living Tribunal and Above-All-Others and sucks them in too. As he put it then he has achieved more than omnipotence. He doesn't just *control* everything in the multiverse he *is* everything.
Now Pip teleports Eros and Adam to where Thanos ought to be but they find a swirling emptiness and the Tribunal's hood on the ground. Then the giant face of Thanos congeals out of the mist and Adam realises what the mad Titan has done. Eros takes himself and Pip away through time, and Thanos tells the Troll there's nowhere and nowhen he can hide. Adam speaks up and the omniscient one is surprised to see him. Thanos says Adam and Eros are strangely difficult for him to see (which is why he only spoke to Pip just now). But now he can focus on Adam and he sucks him in as Adam cycles through his many previous incarnations/costumes (who we saw in the previous GN). Now only Eros and Pip remain to be subsumed. Apart from them he is everything throughout time, space and alternity.
Eros has taken Pip to another time but of course in the same misty nowhere. Pip is angry that Eros left Adam behind, but Eros says Adam deliberately didn't come with them. They are discovered by Above-All-Others (presumably they have travelled to a time before Thanos absorbed him, even though Thanos now is all of time). Pip takes them elsewhere to escape his wrath.
Next stop is present-day New York where Eros leads Pip into an Army & Navy Store. He grabs a backpack, rips head, arm and leg holes into it, stuffs the Troll inside and puts it on. Then they time jump without paying to 1921. Eros has worked out that Thanos can't sense him and hopes being closely attached to him will make Pip somewhat invisible too. Besides he can only do time jumps and Pip provides the space jumps so Eros doesn't want to take any chance of them getting separated.
Eros jumps back to the present day and tells Pip to take them to Thanos' ship where they find Corvus Glaive and Proxima Midnight who say that Thanos left 2 hours ago after talking to a floating head. That head was the future-Thanos and this happened in Conflict. There were also a horde of Thanos' minions called Outriders who Corvus and Proxima now have forgotten. And then they too fade away. Eros figures that Thanos is wiping from time everyone who knows anything about him.
Adam has found himself still himself inside the reality which is now Thanos. He locates Kang's timeship and Kang floating beside it in a transparent 'coffin'. He has a feeling Kang will be useful to counter both Thanos *and* Eros.
Present day Thanos also seems to be within super-Thanos. He shares the omnipotence but isn't in control. He doesn't approve of super-T's goal but is content for now to watch and wait. He notes that the multiverse carries on its business without detailed supervision, which is just as well because trying to keep track of the very-multiple parallel timelines is disorientating, so both Thanos's concentrate on the main timeline. It seems that super-T can't achieve his end until he has absorbed *everyone*, particularly his brother. So Eros' freedom is now essential for the continued existence of reality.
The 2 fugitives are now in Starlin's Bar on Knowhere with the floating head of ISAAC the Titanian supercomputer who advises them that Thanos can not now be defeated physically. Thus they have to find out what his intentions are and then outwit him by playing on his madness. Eros asks ISAAC to calculate when super-T and the universe will end. ISAAC provides the answer and Eros time-jumps there.
Adam has brought Kang's coffin inside Kang's timeship. Super-T is so obsessed with his goal that he doesn't notice Adam exploring his mind and discovering his (still-unrevealed to us) plan.
Eros and Pip arrive at the end of time in what appears to be a featureless white void. But then they spot super-T in the 'distance' and realise they are outside the multiverse (because outside of *him*). And super-T declares an ending, and reality/him explodes.
Our duo have leaped to safety in the present on the Moon at the feet of the Watcher. They have just seen Thanos commit suicide and take reality with him. Then a hologramic message from ISAAC informs them that he won't be able to help them any more because God-Thanos has arrived to destroy him.
Adam wakes Kang from his coffin. The Conqueror doesn't know how he got here. His last memory is of waiting for Thanos (presumably in orbit round Chandilar where the Titan sent him to wait in Siblings). Adam informs him that Thanos betrayed him to future-T who has now become God. He suggests the time-traveller ally with him to defeat the Mad Titan before he destroys the multiverse. In particular he wants him to pick up Eros and Pip from a point in space-time which he doesn't know yet.
Adam hopes they can get away with his scheme because Thanos is still unfamiliar with omniscience, and also he's spending all his effort trying to detect the undetectable Eros. At this point he lets Kang know that Eros is time-travelling using tech stolen from *him*. Adam leaves Kang deliberately without revealing any more of his plan, and heads off to the 'darkest depths of Thanos' soul'.
The Watcher is still watching Eros and Pip mope about on the Moon. Eros hopes that his 'outside the norm' status can give him an edge. He's still seeking a way to exploit his brother's madness. Despite being a psychopath Thanos has demonstrated affection for a few people like Gamora and Eros himself. Eros now plans to skip through his brother's life reinforcing the brotherly bond.
Now back to Adam. Using his version of cosmic awareness he manages to locate Thanos' dark heart on a dead world. He finds a portal to the psyche in the ruins of its civilisation, but before he can step through he is accosted by the memories of his past selves. They don't want him to go there because they fear that omnipotent Thanos will obliterate him and hence themselves. Current Adam insists that the survival of the multiverse is more important than his own, and so they fight. Eventually he grabs the Soul Gem off the brow of 1 of them and steals their souls.
It has been a while since Adam gave up the Soul Gem because it affected his mind. But now he figures being crazy is right for the kind of path he's following, and he enters Thanos' soul. The landscape is very Ditko Dr Strange (I even spot the G'uranthic Guardian among the portals there). He figures each doorway leads to a specific memory. The 1st shows very young Thanos with his parents after smashing a lamp with a bat. His intuition leads him to another door beyond which he finds little Hunger floating in space, in his much-reduced state after his defeat by Thanos in #1-6 of the 2003 series and his reappearance in Siblings. Adam uses the Soul Gem to give Hunger enough of a power boost to do what he did in Siblings - inconveniencing future-T but not by much.
Eros and Pip are on Titan soon after Eros' birth. They run into young Thanos and Eros tells him he is his baby brother come back from the future to tell him how much he loves him. Thanos isn't impressed but Eros assures Pip that repetition will have an effect. Next they visit the teen Titan who has sicced some beasts to kill some bullies who annoyed him. Again Eros impresses on his brother how much he cares. The 3rd stop is the day Thanos fires a missile from an early spacecraft which kills many on Titan including his mother. Thanos reiterates that he doesn't care if Eros loves him.
Within super-T, current Thanos detects these small temporal disturbances and that they are caused by Eros. The next 1 we see is Thanos' encounter with Drax The Destroyer and Iron Man in IM#55. Eros says he's going to continue annoying his brother until he realises he's taking the wrong path in life. Now god-T detects the time-disruptions and figures out who must be making them. And we follow our errant duo to Avengers Assemble #7 where Thanos is confronting Champion, Collector, Contemplator, In-Betweener and Stranger with a Cosmic Cube in his hand. Before Eros can do anything Pip gets sucked into 1 of several coloured balls of light floating around. Eros can't afford to lose Pip's space-teleportation so he follows him in ...
... to an ever-mutating environment Pip dubs Crazyland. Their bodies are continually distorted in ways funhouse mirrors would love to emulate, including splitting into parts. The surroundings are equally weird. Until eventually Pip is able to lock on to somewhere else and port them there. They're back on the Moon with the Watcher.
Thanos within super-T is tracking them and thinks he may be able to point them in a more useful direction than trying to save his soul. He causes their next jump to take them to another time when he had a Cosmic Cube - the end of the Thanos War in Captain Marvel #33. Thanos freezes time within the battle against CM and Drax, and it is the trapped Thanos who speaks through his earlier body to Eros and Pip. They admit that they've been trying to convince early Thanos's that Eros cares for his brother. Thanos laughs and says Eros is a sociopath who cares about no-one but himself.
The scene changes to Drax killing Thanos in Annihlation #4. The dying Titan tells our pair that they don't *need* to change his mind because he already disagrees with future-T's plans. Next stop is backwards to the climactic battle of the Infinity Gauntlet. Thanos stops time again and explains that future-T took control of him in order to ensure his own future came to pass. And Thanos doesn't *like* being controlled. Another jump takes them further back to another big battle in Marvel Two-In-One Annual #2. Thanos claims difficulty in freezing time while being beaten up by Thing and Thor. Eros uses his emotion power to cause temporary fear in the foes. Thanos tells them they must free him from god-T at the end of time so he can help them.
Meanwhile Adam enters another door in god-T's mindspace and witnesses Eros and Pip indeed talking to the trapped current Thanos. Thanos tells Eros to reach into his light cage and pull him out. Eros obeys and it all goes wrong. Adam withdraws from the scene as god-T materialises and thanks our Thanos for luring Eros to him. God-T was aware of what our Thanos was doing all along, and now he has taken the last soul he needs. He tells our Thanos that he only disagrees with the suicide plan because he hasn't experienced his future life yet.
God-T leaves and Adam pops in again. He refuses to free current Thanos because he isn't powerful enough to defeat his future self, even with Adam's aid. He has his own variation of Eros' plan, and that requires current Thanos where he is now. He asks the Titan to trust him as they once shared trust (as part of Adam's Infinity Watch).
Adam uses the windows in god-T's psyche to follow him as he explains his motivation in a god-voice monologue. His life has taught him that existence is a fruitless struggle for supremacy over others. Concepts like love, friendship and loyalty are illusions. The only peace lies in non-existence. So he has achieved oneness with the multiverse so he can save himself and all its denizens from the horror of life by committing suicide. Current Thanos and Adam are determined to stop him.
Adam now mentally contacts Kang and tells him to retrieve Eros and Pip who are on the present-day Moon with the Watcher (obviously before super-T absorbed Eros). Kang picks them up in his timeship. Adam hopes that denying Eros to super-T will upset his plan. He then leaves Thanos' mind to go to the end of time to see what happens. He finds himself in the earlier scene outside the Thanos-verse watching Eros and Pip watching Thanos about to commit reality-cide.
Then god-T realises he doesn't actually contain Eros. Current Thanos senses his opportunity. Super-T *does* explode. But does he take reality with him?
Adam finds himself in a black void. But then he spots a lone glowing spot. As he approaches it extrudes a 'rope' which he grasps, and he's pulled through to somewhere by Kang standing on his timeship. It seems reality has been recreated as it was before, and only Kang, Adam, Eros and Pip know anything happened because they were outside the timestream. And Adam knows why. Our Thanos was able to take advantage of future-T's lapse in concentration to take control of his suicide and redirect the energy back to the multiverse as it was. Meanwhile Kang went back in time and stopped Eros from stealing his time-tech. And he delivered him and Pip to Starlin's Bar as Adam requested.
Adam heads to the Bar to join them. But 1st he gets Kang to take him to another moment in time. This seems to be an excuse to show us a moment not depicted before this trilogy (but here it is a word-for-word repeat of the beginning of Conflict). In Warlock And The Infinity Watch series Adam divided the Infinity Gems among 6 guardians to keep them apart, and he gave the Reality Gem to Thanos! This scene explains why. Thanos knew the Reality Gem was too dangerous to use alone, especially without the Time Gem to undo any errors. Thanos certainly wouldn't want anyone else to have it, and no-one would be foolish enough to try and take it from him. (It is unclear whether current Adam is meant to have influenced this choice here, because he relied on this past alliance earlier in this story.)
Be that whatever it is, Adam arrives at Starlin's Bar but he sits alone, not joining the carousing Eros and Pip. The Guardians Of The Galaxy are at another table, and they notice that Adam has the Soul Gem back on his forehead, but of course they don't know how he got hold of it. (The presence of the alien Ghost from Siblings here suggests that this is supposed to be the same time as similar scenes near the end of Siblings and the beginning of Conflict.)