Spriggan

Spriggan is a large security robot found in the unnamed research facility that was experimenting on the abilities of Child Errors during Shundan Kimi and her friends' childhood.

Etymology
A is a legendary creature, sometimes classed as a fairy, from.

Principles
Despite it's large imposing figure, it is programmed not to harm people and is apparently used to capture them. It is powerful enough to destroy glass and metal. It has four legs with rollers and two arms. The arms can eject cords that it uses to capture people.