DIrishB
The Timeline Guy
I read a theory online that "The Other" - the commander of the chitauri who seems to speak on behalf of Thanos is actually the Grandmaster and is manipulating everyone (including Thanos) for his own purposes. Maybe he is the one who gave Loki the sceptre. It seems unlikely that anyone could manipulate Thanos successfully, but when both Loki and Thanos are involved, everyone is trying to manipulate everyone else. Or maybe Thanos entrusted Loki with the sceptre to help him steal the Tessaract and conquer the earth, but Thanos was expecting to get both back once the chitauri won earth for Loki. Anyway, I'm assuming that the sceptre DOES contain the mind gem until it is confirmed otherwise.
That's a cool theory. But like I said, I just don't see Thanos willingly giving up a gem even if it's only temporary. It's possible the Other did so without Thanos' knowledge, and if he does turn out to be the Grandmaster, that'd be awesome. And it would lend credence to the Other being able to manipulate Thanos. But I don't see Thanos allowing the Other to give Loki a gem, since I'm sure Thanos has at least some knowledge of who Loki is and his capabilities and penchants for trickery. So yeah, the Other/Grandmaster theory would be the only way I can see it working, since it's done without Thanos' knowledge. Of course, I think it's safe to assume Thanos has done his research on the gems, and knows the forms or likely (or at least possible) locations of at least some of them (hence him having Nebula and Gamora tracking down the orb in the GotG Prelude #1 comic, though he was wrong about the location). The fact Collector knew the exact and accurate location of the orb (revealed in the GotG Prequel Infinite comic) shows there are some who know more about the gems (or certain gems, anyway) than Thanos. So that could lend credence to the Other/Grandmaster theory.