An illusion's domain
[OP: ]
The domain summoning. A skill that many strong (Purple) ranked creatures possess in simple or unique names. And no, this isn't domain expansion.
It mostly varies a lot from the type, kind, and individuality of the creature, but the general purpose of the skill is to summon, change, or turn the surrounding area into a terrain that's perfect for them.
It could be a place that they had created in the past or the home they lived in for most of their lives, but when one summoned their domain, they were taking over a certain space around them under their sole control.
It was, in true meaning as a skill, only something that energy beasts possessed, or some uniquely strong individuals were able to gain as their branch origin skills.
The ones who gained it naturally were held highly in today's time, but that wasn't the only domain summoning or domain creation present in today's time.