- A heartless is a creature that is made up of corrupted and decayed bits of hearts. Because of this they find themselves hungry for hearts and consumed with the desire to collect and eat as many as possible. There are two different kinds of heartless - those that have formed naturally due to the darkness and negativity in the world around them and those who were manufactured by Xehanort's machines.

- Canonically it is impossible to play a sentient heartless. It's made clear that while Nobodies become smarter and more human-like the stronger they are the reverse happens to heartless. They become more animalistic and a slave to their primal desires as they become stronger. Staff, however, is willing to bend canon some in order to allow this as a race. What this means though is that no starting character may be a heartless.

- Much like Dream Eaters Heartless would have two forms, one that is more animalistic and a fully human form. The 'heartless' form can either be one shown in canon (within reason - if the heartless was ever used as a boss-type character then it's highly unlikely staff will okay it unless you impress us with your previous character) or an original one. Any original forms must be able to blend in with canon forms.

- Keep in mind that no canons can be referenced in their histories.