Artifacts are quite a bit different, and their inscrutability is tightly tied with their thematic role in the game - they aren’t overtly controllable, the player can’t make or seek a specific type or power out, and there’s costs.
They are different because they are intended to be inscrutable, to make the player wonder how they could be and just how different things are in this alien world that they came to be. That they are very much not of this world, and of something beyond it, they (much like the portals themselves, or how the slime makes things mutate the way it does, or where it gets so much energy, or how the necromancer and master powers work) are the kind of “magic” that actually reinforces the feel of the game - the player should be able to eventually understand the action of the things he can control, but the player should never be in control over the forces that are rending the world apart, and the fact that these forces are outside the players understanding is important - it’s not that they are magical, it’s just that they are so alien that they might as well be. The artifacts are the players opportunity to interact with the forces in a more personal way, but it’s hard to say he really controls them even if he possesses them.
