The Dark Elves' Aether, the Frost Giants' Casket of Ancient Winters, Surtur's crown and the Eternal Flame were all galactic treasures.
But Asgard, ruler of the Nine Realms, had no use for these things, and so they were just sealed away in Asgard.
But for other people, especially Luke, who was obsessed with research, these were good things he couldn't miss out on.
Odin, ruler of the Nine Realms, wasn't interested, but Luke, 'ruler' on Earth and a galactic newbie, was very keen on them.
In any case, the Space Stone had been given to the Level 1 clone and had been taken away from Asgard.
For the Level 3 clone, taking risks wasn't a problem at all.
Something that could destroy the Level 3 clone had to be an existence on Thanos's level – and that was only if the clone couldn't run away.
It was just sneaking into Asgard's treasure vault on the eve of its destruction. So what if Hela noticed?
