Shivie Aika is Aika Sumeragi's super-strong, beautiful and sexiest form where the mysterious Lagu turns her skin to brown and her hair to blue. It also barely covers her private areas has a mind of its own.
This has a strong connection to Lagu and Aika Sumeragi as she can come out when she feels her host in danger and will kill anything that threatens her. Aika has some control when the situation is not as bad.
Shivie Aika is the strongest person in the series and Shivie Neena tries her own variant of the power but was of little match.
Rudolf Hagen created an device that deactivates this form and reduced it to a ball, but this method didn't work the second time.