While building your custom permission set in the Permissions Builder, you'll encounter the Superadmin permissions.
These permissions are intended specifically for users who require elevated access to features that are beyond the scope of standard user capabilities.
Superadmin permissions can be found in the Imports, Permission Sets, and Employees & Contractors sections, and are easily identifiable by the "Superadmin" tag in the permission set builder.
Granting Superadmin Permissions
While Superadmin permissions provide extensive control, keep in mind that with great power comes great responsibility!
Use discretion and limit these permissions to those whose roles require such elevated access levels.