Foreigner's Token would be a weapon they've used in the past, but no longer are proficient with due to their loss of memories: Their "Sapphire Stain Saber".

It looks like a perfectly normal weapon, though no longer as well mantained. Foreigner can remember a recent story regarding it from the first day of their new memories, often bringing it to talk about it and show it off. What gives it it's name is an odd looking, translucent stain akin to ink which they admit was already there for as long as they could recall, and can't seem to scrub it off, nor have any studies point out what it is, at most designating a cluster of proteins in said stain