For any fellow translators checking this: Alice sort of interrupts herself in the bottom right panel, so this is my best interpretation of what she means. 陣 here is clearly meant to be understood as in é”法陣, not as in a military base. I decided to borrow the term alignment from archeology as "magic circle" doesn't really do this setup justice. "Mystic marker" might be an alternative to "ritual element". I avoided the use of terms involving "tool" since these imply something smaller and portable. If you have better ideas, feel welcome.
Updated
The old owner....Have you noticed?They were doing some kind of experiment.blub...I thought the lake was just naturally emanating magic, but...The alignment channels magic and pushes it inwards.Yeah, it's all part of this.There's ritual elements... an alignment?...This is a large-scale setup.It uses this entire space.