I wanted to share what I have recently done for a player who's going for a Signature Item as part of their Player Story. This is a character who we 'recreated' from 1e. His character had been Sidhe blooded "Child of the Sea" with Glamour Magick, mostly around sea-style abilities. When we redid in 2e, he was a Knight of Elaine and wanted to get his Sidhe Sword back in hand. In addition to the normal "Signature Item" abilities, I've added a few others (Same cost as I didn't feel these were going to make it overpowered).
Oidhche Tonn "Night's Wave" - Sidhe Sword
These properties are always on:
1) Always know when a Storm is coming
2) You cannot drown while you have the sword in your possession
3) You can see clearly underwater even in the darkest depths of the ocean while you have the sword in your possession
4) Gain 3 Bonus Dice instead of 2 Bonus Dice on a Sailing Risk (Spend Hero Point) while you have the sword in your possession
5) Once per session, you may spend 1 Hero Point to heal a ship of 1 Critical Hit
The hilt is made of translucent crystal, with a lapiz-lazuli gem set into the pommel. The blade is a strange blue-gray metal with ice crystals that constantly form and melt upon the crossguard. The hilt is always cool to the touch.