Q8: This one is easy enough to answer for all of my OCs; at a practical level, I wouldn’t consider any of them to be “the only one of their kind,” since none of them are/were the sole member of their species. (I would consider engineered/mutant characters like Elfilin, Queen Sectonia, and the Master Crown, for example, to fall into this "unicorn" category.)

Some of my OCs are unique in other ways. Zed is the only N-Z on the planet where they and Tillda live, for example.

Q10: Zed doesn't, really. Tillda holds grudges sometimes, but I would say they're mostly superficial. Of all my OCs, Miz-Baranez (the N-Z General) is probably the least forgiving, and Cardnyl (the Jamba priestess) is the most forgiving.

Q21: All of my OCs are adults, though their actual ages vary greatly. Nan-Zee and Zed are the youngest and the orange ball is the eldest.