Fortius Reading Order

The Four Knights (Novella Trilogy):
The First Ember
Key of Memories
Knights of the End

Darkest Depths:
Forsaken King
Wild Spirit (Short Story)
Lost Sacrifice
Rising Night
Scattered Fragments (Short Story)

Chaos Awoken (Short Story Trilogy):
Fading Light
Seeking Darkness
Brightest Spark

The Elementis (Novella Series):
The Sword of Unda