The problem of having one gem is the desire to have them all. To see the gauntlet right there for the taking was a tempting sight, but Loki knew better than to take such a relic. He'd seen what could happen and he knew the consequences better than most. Thanos had made sure of that.
Holding the little purple gem up to the light filtering from his window, Loki smirked, wondering how long it would take for Odin to realise that two of his gems were gone.
Giving Victor the Soul Gem was a gambit. A gambit out of boredom that could ruin him in so many ways, but it would do what other banal activities hadn't been able to do: interest Loki.
Victor's refusal to reveal to him what his plan was frustrated him, but since when did they ever share their full plans to each other? Victor undoubtedly will tell him just a portion of the truth and then hope Loki to trust him on his word. The less the mortal told, the more likely it would be that he planned to betray Loki. Not that he didn't expect a betrayal, but that's why he had the Space Gem.
It would be pure folly to trust that power-hungry mortal with such an item and not be able to wrest it from his grasp when their working relationship turned sour.
The Space Gem was no real counter for the Soul Gem, but having control over space was not to be underestimated. It would give him enough time to escape if his friend tried anything against Loki, which was an inevitable eventuality. Once their relationship was broken to that point, the escape would also provide him a small cushion of time to plan accordingly to wrest the Soul Gem from the human's grasp.
Of course, Victor wasn't the only player he had to be aware of. One other knew of the whereabouts of the Soul Gem and he would be watched carefully. Though a clone of another, weaker Loki, Chaos, was a being that hungered for power even more fiercely than Victor von Doom. He'd revealed the gem's whereabouts, however, just for that reason. Two beings, desirous of a gem neither of them should possess meant that they could be of use to him in their fumblings and possibly even drop the soul gem right into his waiting grasp.
Neither the Soul Gem nor the Space Gem ought to be on Midgard and in time, Odin would discover the theft. Yet, Loki wasn't scared. No, he was excited about that moment just as much as the moment where Victor would double-cross him. All of it was according to plan, a plan made from boredom to cure him of his restlessness. There really wasn't anything like botched plans and failure, really, especially when the final failure and defeat could be placed squarely upon the shoulders of others.
Tucking the gem back into its pouch, Loki slipped it away again in a secret, cloaked compartment, out of sight and detection. For the time being, it would remain where it was. The game was still young and the players yet to be completely assembled. There was no use in bringing out a trump card too early.
