Some edits I don't remember making. Just uploading it to not invalidate my saves. Below is the original description by rottensunlight@gmail.com.

 This addon is supposed to alter the cursed/Darkness tree

to make it useful, while changing as little as possible. I have long
since gone past "as little as possible". I also added the Inner Darkness
tree, an advanced tree meant to supplement Darkness the way that Advanced
Shadowmancy supports the Shadows tree.

-- Creeping Darkness: I lowered the cooldown, I set the number of seeds

            of darkness to increase appropriately with talent
            level. The darkness now inherits a weaker version
            of the debuffs of other debuffing abilities you
            learn once those talents reach level 4. In
            particular, Dark Torrent, and Dark Tendrils. The
            strength of the debuffs are determined by the
            talent level of the talents from which the
            debuffs are stolen, and your mindpower. The
            density of the darkness is based on mindpower and
            talent level, filling up to 75% of the given aoe 
            at 100 mind power and talent level 5.

-- Dark Vision: I increased the max range of the vision to 7

            squares, to enable one to target Agony and
            Hateful Whisper correctly. I also boosted the
            movement speed buff slightly.

-- Dark Torrent: I set the ability to always leave creep behind

            instead of randomizing a core part of the ability.
            I also increased the damage very slightly.

-- Dark Tendrils: I made it faster, with scaling based on talent

            level, and the damage of the darkness it leaves
            behind is improved. I also added an extra
            tendril at talent level 6.

-- Grudge: This gives you a hate/life heal, while

            inflicting the Grudge debuff, which will take
            back the life it healed, plus a little more, 
            making you bleed creeping darkness all the while.

-- Veil Walk: This is just a short range teleport, with the

            ability to switch your place with opponents. It
            gains range with talent level. It is instant if
            you are stepping into your creeping dark. It
            also cuts fear immunity, dark resist and mind
            save when you switch with an enemy.

-- Heartless: This sustained ability burns hate to deal a

            small amount of dark damage on top of every
            blow you deal, and also makes enemies leave
            behind pools of darkness when you kill them.

-- Dark Blood: This ability is pure damage smearing. It collects

            all the damage you take in a single pool and
            portions it out to you over the following turns
            at a set rate.

I have also unlocked the Fears tree, and changed it to be like the version
of Fears in HousePet's afflicted rework. However, the fear effects
themselves have been altered. In particular, the fears that inflict
damage are now allowed to crit, and some of the fears were locked so as to
not inflict brainlock. This has been removed.

I have significantly buffed Gestures to the point of being absolutely brokt,
in the hopes that they'll make a possible alternative to psiblades. I'll
just have to keep buffing them until you don't have to take psiblades, and
then tune them until they aren't crushingly oppressive.