Seek out Gregan Brewspewer in northern Feralas. From him, learn how you may acquire the Videre Elixir, then return to Donova Snowden in Winterspring.
Now, what's this? Linken... FORGOT?
Oh, I see... Lost his memory...
Well, here is his sword. It's not complete, though. I know of the one that can finish it, but... speaking with him may prove difficult.
Listen, I know of someone that will be able to help you. It's too much to explain right now, but you must somehow acquire a Videre Elixir. The only one I know that can help you with that is Gregan Brewspewer. He's hard to track down, but last I knew he was camping in the wilds of Feralas.