So what's going on here? He reintroduced Thanos first as Warlock's ally, then as his opponent in a storyline known as the "Second Thanos War" that ran until 1977.
Retrieved December 10, 2017.
It doesn't matter if it's Earth or Asgard, so long as he's a king.
As of Infinity War, Captain America and Iron Man still have not united.
Sure, the Collector was a shady dude who wanted the stones for his own purposes, but his dastardly plans were crushed when Thanos showed up and burned Knowhere to the ground.
The result is satisfaction.