The Orc Disaster is the evolution of an Orc Lord and is a Demon Lord Seed.
This creature is extremely powerful overall, crushing the resistance of five A ranked beings, all highly skilled, when he had only recently been born. He possesses all the powers amassed through Starving Ones but unlike an Orc Lord, he retains the wisdom to make proper use of them.
The Orc Disaster, for all his power, is noted to be in the process of evolution. As is true of all Demon Lord Seeds, he must kill a fitting number of humans to evolve into a True Demon Lord, which is evidenced by the fact that Gelmudo had planned to have Geld destroy a human city after he became a Demon Lord. Ultimately, however, this was never achieved as Geld met his end at Rimuru's hand soon after assuming this form.