Exorcist Techniques, as the name implies, are special techniques used by Exorcists to exorcise demons which anybody can learn. To use them, one requires Precept Power.
Basic known Exorcist Techniques are XR-Cism Bullet & Pentagram Techniques like Pentagram Sword and Pentagram Shield.
There are also advanced Exorcist Techniques that only a few can use known as Crest Xr-Cism.