how does potential work in terms of hwo many you can use on a weapon?

You can potential an item with slots no matter if their used or no (we have pendants with slots and thus can be potentialed but at the same time we have some with no slots and they can't be potentialed), the item when potentialed can come randomly with 2 or 3 lines but if you have an item with 2 lines you can use the orange miracle cube (cash item (can't remember its name)) for a chance to make it 3 lined.