X-men comic about a citadel with an "all-powerful" gem

Question

Back when I was a kid I remember reading an X-men comic where they get transported to some sort of citadel in another planet by a villain, in order to retrieve some sort of gem.

What I remember about it:

• I read the comic around the early 1990s, although it could be older.
• The villain wanted the gem but could not get it himself. I can't remember why.
• At the entrance to the citadel there were giant statues of other races of the universe, Kree and Skrull among them.
• There were several X-men involved, though I only remember Wolverine and Havok.
• The citadel tests anyone who enters it, and in the end only Wolverine passes the tests.
• When he arrives to the gem, the villain gets to Wolverine and kills him, but in doing it a single drop of his blood hits the gem and Wolverine regenerates entirely from it.
• Wolverine then aquires (almost?) omnipotency but finally decides to give it up.
• The comic ends (I think) with a phrase saying humanity has passed the test, unlike the races represented by the statues.

Anyone remember this comic and can give some details?

Answer 1

This is X-Men Annual Vol. 1 Issue 11 from 1987. The villain in the issue is Horde and it is his one and only appearance. Horde has a shard of crystal on his forehead and the gem he's trying to get is the full crystal, the Crystal of Ultimate Vision.

We can see the entrance to the palace, the Citadel of Light and Shadow, here with the statues lining the way:

Click image to enlarge.

Horde eventually kills Wolverine as he gets to the crystal but as described a drop of his blood lands on the crystal and he regenerates:

Click images to enlarge.

Wolverine does gain full omnipotence but gives it up almost immediately when he realises he starts talking like a god and destroys the crystal. I don't believe it ends with the message of passing a test though.

Answer 2

Uncanny X-Men Vol. 1 Annual #11, published in 1978 1987

As per the description here:

the X-Mansion is attached by a demonic-looking villain who calls himself Horde. He easily bests the X-Men and teleports them away from the mansion, where he explains that he is an alien, but also a mutant of his race - and an immensely powerful one at that.

Then the shenanigans with the gems.

Horde appears and tries to claim [the gem] for himself. Wolverine throws himself between Horde’s spear and Storm, saving her life, but impaling himself in the process. Horde then tells him, “You have a noble and courageous heart, Wolverine. I’ll keep it as a trophy!” and proceeds to tear Wolverine’s heart from his chest.

After being regenerated wolverine destroys the gem.

The crystal also imbues Logan’s new body with enough cosmic power to kill Horde. Rather than keep the power for himself, however, Wolverine gives it up as soon as Horde is defeated and destroys the crystal. Good call, Logan.