Guardians

Guardians were the plural title for Guardian. The Guardians were two Jedi assigned to protecting the cave of the resurrection crystals. They were given immortality, and could not be killed or die. They were excellent warriors, and were able to kill very well and fast. They could be harmed in combat, but never killed. The only way they could die was when the galaxy was destroyed. There were only 3 guardians to have exsisted:

The Old Jedi The Young Jedi Jacen Solo