I'm almost certain that the Sphinx's Ka stone, Karla's Moonstone, Basilisk's Alpha and Omega stones, the Ulysses' Bloodstone and and the rest of those gems are ancient kree artifacts as well. Basically a poor mans infinity gauntlet if assembled. Too bad no one has ever attempted it... As it stands, when a stone is paired with it's duplicate, the user becomes a phucking boss; ie, Sphinx with dual ka stones, Baron Zemo with dual Moonstones and Basilisk with the alpha and omega stones.