We already did magic systems. I led that topic, while Cosmere Villain, Non-Cosmere Characters, and Cosmere Worlds where run by other people, whom I am too lazy to check the identities of.
Also, @Zizoz, you're totally right. Nightblood does count as inanimate, however I was joking when I suggested the topic. It could work though; some people might really love Dalinar's Shardblade, for instance, or Allomantic Vials, or The Bands of Mourning.
Edit: (Though it would be difficult to decide what items would actually be in that tournament)