Who is Patrin from Heretics of Dune and what is their importance?

Patrin is a native of Gammu, Patrin is the Bashar Miles Teg's most trusted aide, who he puts in charge of protecting the latest Duncan Idaho ghola. With a long, pale and wrinkled face, Patrin stands guard in the exercise courtyard with a heavy lasgun at the ready. As the danger to Duncan increases, Patrin devises a plan to hide Teg, Duncan and the Reverend Mother Lucilla, Duncan's intended Imprinter, in an ancient Harkonnen no-chamber that he finds as a boy exploring the forest but reveals to no one. Teg does not realize that part of Patrin's plan is to serve as a decoy, pretending to blast off in a no-ship to obliterate signs of the no-chamber. Teg mourns for his old friend and hopes he died swiftly and painlessly.