Lion Helm
From Warhammer 40k - Lexicanum
The Lion Helm is a sacred object of the Dark Angels space marine chapter. It is said to have been worn by Primarch Lion El'Jonson and takes the form of a winged MkVII space marine power armour helmet. The helm is carried by a Watcher in the Dark. Built into the helmet is a protective force field which can be activated even when the helm is not being worn. The Lion Helmet is currently worn by Supreme Grand Master Azrael.
