In the sky.
A legion that consisted of Soul Slaves in the millions covered the sunlight like tidewater. They cast a huge shadow over the grounds beneath.
They were once at the apex of the food chain from the corner of the world of which they came from. Their worlds had since been dominated by the sorcerer's world.
When they had submitted to the will of the sorcerers, they had sold their souls to the 'evil' sorcerers and followed them in their conquest around the foreign worlds.
The incessant killing and absolute submission to the sorcerer's will became their living principle.
In the neverending battles of the sorcerers, the weak perish while the strong survive. There's always a fresh batch of Soul Slaves joining. Soul Slaves that had survived became stronger in each battle.