Memories of Vlast

do i need to keep this item after i get it? is there a real benefit to having it around?

Well, the wiki says you can get extra copies after you're done the achievement, so there's little value in holding onto it.

Extra copies may be obtained by speaking with Adisa after completing the achievement.

Sorry I should have been more clear. Is it ever used for anything else?

I don't think so, but even if it was you could just get another one from the vendor to replace it.

Thank you