A fan (hand slot) that caused knockback (use the trampling-scatter code) and provided a good air shield would probably be thematic for Air. Possibly appropriate for a TC role-player.
An assassin-themed throwing knife (misc slot) that gave a single high-precision AP throwing strike and a stealth bonus (only for the already stealthy) might also be niche-but-thematic.
I still like my old idea of a unique blood weapon which essentially consecrated kills (those who died by the weapon having some chance to generate temple checks).
If we were being even crazier, it'd be funny in a rather twisted way to have a Flayed Cloak (blood/death) which had a Horror Mark aura, perhaps boosted Blood, and which also had high Fear (as sane people run the heck away from the Accursed One).