The sith younglings

The sith empire has fallen, and their sith brothers and sisters have been slaughtered. Before the end their master performed a dark ritual using ancient sith artefacts which gave his apprentices ever lasting youth.
In order to save their order they must stay young and unaffected by time.
Now years have passed and a new power is rising and this may be their chance to bring back the order of the sith and all its revenge in the galaxy.