The Hidden Forest

Hi,

can a character obtain and wear both old and new donor weapon (SK in my case)?

Of course you can but you will obviously not be able to dual wield them You will be able to equip them in the various slots they fit in (primary, range, back) and get the benefits of their focus. If some high ends SK have the donor 1 in inventory it's because they are wearing better donor items in back/range and prefers the effects of donor 2, but they can still use the life drain clicky from inventory.