DARK ANIMUS BELONGS TO THEGOLDENDRAGONESS. PLEASE ASK IF YOU WANT YOUR DRAGON TO BE A DARK ANIMUS. You are welcome to use the Dark Animus (with permission from me) as long as you don't go crazy with it (etc. making everyone in your fanfic a Dark Animus then unleashing them on Pyrrhia). Dragons that have dark animus often use the slang "It takes everything in me not to go dark on (insert name)".
Black eyes, grief and strange behaviour, like for example a SandWing feeling right at home in the ice. These symptoms start after their 6th birthday.
I will add to this list after more of A Dying World is published.
If you have Dark Animus, you cannot control it. It is driven by dark emotions, like sadness, anger, hate, etc. Dark Animus dragons are generally the same level as Animus dragons, but are weak because they cannot call the power at their will.
Every few centuries, a dragon like this will be born. Dragons kill them the instant they know of the Dark Animus. Sometimes they lived to adulthood and nearly destroy the world. One brave hero would always sacrifice themselves for the good of the world and for the Dark Animus. No Dark Animus has lived for more than 50 years.
The Dark Animus dragon's appearance changes when they wield their power. When they first use their Dark Animus their eyes go black. Everytime they use it, something else changes in their appearance. Their scales getter darker, they develop a black underbelly and large spikes grow on their back. Every Dark Animus has a diamond on their forehead which glows when they are using their power.