I never did understand this, as the Chtaruri seemed sentient, and not robots, but more carbon based life forms much alike our good selves.
That said, there must've been some form of link keeping them alive; maybe it was just their outward appearance that seemed humanoid, and they were actually robotic or something underneath?
What a monster he was.
I know
@KRYPTON INC. has expanded on this already, but to go on further...
I never did understand why they needed to return the stones anyway... At the end of Endgame, we've already got a bunch of different timelines, ones that either happened, or were changed.
- Loki surviving (thus creating another timeline)
- Thanos leaving his timeline (thus there's a timeline where he just vanished and didn't go on to collect the stones and assault Earth).
- There's a timeline where Steve fought himself (but that's gotta' be a different one again else he'd have already remembered doing just that).
- There's a timeline when Asguardian soldiers would've had to explain to Odin that a rabbit was caught running around Asgard and disappeared.
- Then there's Steve deciding to remain in the past to marry Penny, when she already had a different life with someone else, so Steve either erased her old life, or is responsible for yet another alternate one.
It then begs the question of whether they actually returned to the timeline from where they left - I'm assuming they did (must be something to do with the pym particles and quantum universes) but through Endgame we actually visited a bunch of alternate realities that are all just as real as our main one, so what difference was there between returning the stones and not doing?
Maybe Bucky's strand enabled longer life?