In Earthdawn (ED for short) there is a thing called Thread Magic. You MUST use it to gain powers from items (and you can even use it to bind your group together so they can do some things better).
Magic items in ED are not (usually) purposefully created. They are usually the items of mighty heroes of the past that have attained reputations and legends which are the true power behind their, well, powers. The Sword of Jax the Mighty, is a magic item because it was the Sword of Jax the Mighty.
Thread Magic should be thought of as a sort of Item Attunement: you use it to unlock the abilities of the item in question, but to do it you must gain information about the item - generally specific information tied to the ability you are unlocking. You must do it in order: that is, Thread 1, then Thread 2, etc.
It costs both experience (Karma in ED) and time/effort in tracking down the information needed. When you get the information, you spend the required Karma (100, 200, 300,....up to thousands) and use your Thread Weaving Talent (read: magical skill) to attach a thread to the weapon. If I remember right this thread connects you with the weapon so that you can use the ability (even if it is just additional damage). Someone else getting the weapon cannot use the abilities you have unlocked until they remove your thread (by killing you or a magical ritual) and attach their own - though they may be able to attach threads without removing yours, hmmm, something to look into.
Hope that helps. I was getting ready to run an ED game (and have played/ran games in the past).
PS: The Thread Magic of ED can get very complicated when you are talking about an entire PC group connecting threads to each other and their items, and maybe even their animals. Very complicated.