The Stormguard is the remnants of the old army protecting Queen Himiko and the island of Yamatai in Tomb Raider (2013). It consists of Oni and Samurai who have lived an unnaturally long live and now protect the remains of the dead queen from any intruders, even Mathias's attempts to resurrect the queen.
One of the more prominent characters of the Stormguard is their General. Lara finds his remains near the end of the game in an underground cave, where he committed Seppuku. Also, throughout the game, Lara finds documents left behind by the general (General: The Oath and General: The Conquerors).