So I extracted a legendary item from a weapon, If that is selected in the cube menu does that mean it is active or do you somehow affix it to a different weapon? If that makes sense lol
Yes! When you extract powers to the cube the cube saves them like a menu. You have three menus. One for weapons/offhands, one for armor, and one for jewelry.
You can browse the menu of powers you have collected and pick one for each of those categories. That power is active for you as soon as you select it. You do not need to apply it to any items. You can change the selection any time you want when you are in town. It does not cost any gold.
To see what you have selected when you are not in town near the cube, you can hit the C button to view your character and use the Details menu to view additional skills (resists, regen, etc). At the bottom of that list is the Cube powers.
Thanks so much that was really helpful!
Over on EU (where I can do embedded pictures) I responded to someone who was also unfamiliar with how the Cube worked. Linking in case others might find it useful…