I think I read that a while ago and cant remember anything other than he was some kind of vampire. If i read it it was like over 10 years ago. I might even have it in a box with my comics over here.
He was from the ultraverse and LT stated that with the IG he could rule over both the prime Multiverse and the Ultraverse, and he was defeated by surfer
But on a more serious note, Spectre as suggested in the openion is at full power which means that it have bounded with the sources and thus have become second only to the Presence (the way I understood it, I could be wrong if so please correct) in terms of power, Second to the supreme being sounds like someone I know what about you?
The am fought supergirl and it wasnt a stomp. Thanos defeated two celestials,and all the other abstracts at once while Spectre remained in a coma after he failed to destroy the Am.
You brought up a low showing but not for Thanos with the ig. Thanos imprisoned all who opposed him. While the Spectre failed to stp the Am permanently. The Am wasnt as powerful as Thanos with the ig was either.
Gender: Male Location: somewhere within time & space
When Rune first had the IG, the Soul Gem was fighting to control Rune,
this is why SS was able to blast the IG off his hand.
(speculation)
Also, LT might've amped SS,
after all, he used him as an avatar.
It's not really that simple.
Thanos only wanted the 616 Reality (power of the Multiverse/Foundation of the Omniverse)
So looking for Thanos doing awe-inspiring feats (outside of that) with the IG
is a moot avenue to follow.
But if we take into account everything the IG and/or Gems have done,
then you got some amazing feats.
Like,
the Incomplete IG treating the UN like a b*tch.
the Incomplete IG merging 616 and a duplicate 616 in an instant.
4 Gems creating Realities back to back continuously and stacking said Realities.
(the Omniverse was going to collapse)
2 Gems reverting all that Time/Space created by the 4 Gems thus nulling all those Realities.
Bottomline:
Only the LT proved to be superior to the Gems (on panel and in the bios)
The IG makes the wielder "god" beneath the LT.
The LT represents one who is above even "gods" ...
Nebula who's by Thanos account wouldn't be capable of handling the mantle of omnipotente still defeated the Cosmic Beings, even though she was unfamiliar with the IG and it's power and had problems comprehending the imputs from the IG.
Very likely.
And Full powered Spectre has been shown to be second only to the presence and at the same time represent a power that even the presence should fear, further more Like the Gems could cause the destruction of the Omniverse (all of Marvel) so was Spectre holding back the Anti Monitor who was going to destroy all of DC (a Multiverse but still all of DC). And Spectre is basically the right hand of God from what I know he is given the power (when he has a host) to preform whatever task is required of him (full backing from the presence). And I know you hate crossovers but the JLA/Avengers is canon and in that Spectre overwrote the combined effort of the prime marvel universe being merged with the main universe from DC.
The items used was, the DC items the Spear of Destiny; the Book of Eternity; the Orb of Ra; the Psycho Pirate's Medusa Mask; Uthool's Green Bell; Nyorlath's Silver Wheel; Calythos's Red Jar; and the Green Lantern Power Battery of Kyle Rayner; and the Marvel items being the Ultimate Nullifier; the Evil Eye; the Wand of Watoomb; the Casket of Ancient Winters; the Cosmic Cube; and the Infinity Gems
You should know first hand what the infinity gems and the Cosmic Cube and the Nullifier is capable of. And again Spectre overwrote them.