User blog comment:Skeith9/Heroic Spirits Speculation/@comment-42.118.15.228-20140818003501/@comment-5739199-20140818164912

It's better to just think it's always active.

Like how Saber's Magic Resistance is automatic, she doesn't have to "activate" it, if she is hit by magecraft it will just be cancelled automatically. The same with Riding skill or Independent Action.

The only ones which arguably could be switched on and off are Presence Concealment and the Caster skills.