Discord is a disease of the spirit that disrupts a celestial's connection with the Symphony (for angels) or jangles their personal symphony (for demons). Most celestials are about as keen on the idea of Discord as humans are about the prospect of getting cancer. Discord can be corporeal, ethereal, or celestial in nature; celestial Discord is particularly bad, because it disrupts natural Essence regeneration. Celestials typically develop Discord through repeated dissonance -- three notes of dissonance can be consciously compacted down into one point of Discord, as an act of desperation.
Demons can sometimes get away with a low level of Discord, but most angels cannot. (Malakim are typically destroyed for having any Discord whatsoever, but in rare occasions, they may acquire enough to become dark) Discord can be concealed somewhat in Corporeal form, but it is hideously apparent in Celestial form. It can only be removed through the intervention of a Superior, and Superiors (especially the Infernal kind) might not find it worth the effort.
Calabim start with a single type of Discord, at a level equal to the number of Forces they have of that type. (E.g., a 4/2/3 Calabite might have a level 4 Corporeal Discord, a level 2 Ethereal Discord, or a level 3 Celestial Discord.) This Discord is part of the Calabite's mangled nature, and cannot be removed except through Redemption.
Dark Malakim are so naturally discordant, they can use it to their advantage, enhancing their forces and forcibly removing Essence from the Symphony. However, this inevitably comes with a heavy cost which leads to self-destruction.
Discord effects your ability to gain essence. Every sunrise (or sunset for demons) you will need to roll a single d6. If the result of the d6 is greater than your highest discord, you gain an essence as usual. Otherwise you gain no essence for that
Geases[]
Geases, supernaturally-binding promises, are also considered a minor form of Celestial Discord, and (provided they aren't "active" at the time) are barely noticeable even in Celestial form. That said, Superiors will probably spot them, and Archangels are liable to be very unhappy about their empowered servants owing favors to someone on the other side. These "hooks" are just about impossible for even a Superior to remove without doing catastrophic damage to their bearer.
Discord from Chargen[]
Characters can come onto the stage with preexisting Discord, and receive 3 Resource points per level for it. This is very hard to incorporate into an angelic concept, but is not unreasonable for a demonic one. Geases, being much milder than most forms of Discord, are only worth 1 point per level. To add Discord at character generation, please speak with charstaff.