As the Sorcerer Supreme and this world's guardian, The Ancient One was also the powerful being who controlled and protected the Time Stone. Even Odin would not be able to obtain the Time Stone from her.
There were only two ways to acquire the Time Stone: become the next Sorcerer Supreme, or take it from the Sorcerer Supreme by force!
This unfamiliar invader was obviously not the new Sorcerer Supreme, so only the other possibility remained.
"You killed the Sorcerer Supreme?"
"No!" Yinsen immediately denied it. He refused to take the blame for that. "Besides, I even helped The Ancient One deal with a few minor troubles that had plagued her for years."
"..."
Odin considered it and did not doubt Yinsen's words. A powerhouse of this level would likely disdain telling such a lie. Besides, Odin could see that Yinsen was determined to obtain the Infinity Gems. He probably could not be easily fobbed off.
"May I ask you a question?"
"Go ahead."
"What exactly do you intend to do by gathering the Infinity Gems?"
As the King of the Gods of Asgard and guardian of the Nine Realms, Odin believed he had an obligation and responsibility to protect this universe. If the other party intended to use the Infinity Gems' power to do something that threatened this world, then even if he died here—or even dragged all of Asgard down with him—he would not tell this man where the Aether, the Reality Gem, was located.
"I know what you're worried about!"
Yinsen did not conceal his purpose, since he had no intention of harming this world.
"I want to use the Infinity Gems' power to go home. I won't cause any harm to this universe."
"Go home?"
From Yinsen's words, the well-traveled Odin guessed some details: this powerhouse