Troll Guardians are in an eternal state of block which can only be broken by heavy attacks. Doing this will stagger the Troll opening them up for a magic blast. Troll Guardians spawn in the open world and in dungeons. They usually spawn in pairs but can sometimes spawn in large groups of around six or eight.
Troll Guardians only have one finishing move animation currently avaliable:
The player grabs the Troll's shield and smashes the Troll with it until it impales the Guardian.
Guardians can do large amounts of damage and stun the player with their attacks.
Guardians can be difficult to deal with when in large groups.
It is odd that Guardians only carry a shield and not another weapon along with it.