SOTER was the spirit (daimon) of safety, preservation and deliverance from harm. His female equivalent was the Daimona Soteria.
In the Orphic Hymns Praxidike was identified with Persephone, Soter with Zeus, and and her daughter Praxidikai with the goddess Erinyes. Soter and Ktesios (the son of Soter) were also cult titles of Zeus.
Aeschylus, Seven Against Thebes 223 ff (trans. Weir Smyth) (Greek tragedy C5th B.C.) :
"When you invoke the gods, do not be ill-advised. For Peitharkhia (Obedience) is the mother of Eupraxia (Success), wife of Soter (Salvation)--as the saying goes.
So she is, but the power of god [Zeus] is supreme, and often in bad times it raises the helpless man out of harsh misery even when stormclouds are lowering over his eyes."
Suidas s.v. Praxidike (trans. Suda On Line) (Byzantine Greek Lexicon C10th A.D.) :
"Praxidike (Exacter of Justice): A deity whose head alone is venerated. Mnaseas [Greek C2nd B.C.] in his treatise On Europe says that Soter (Saviour) and his sister Praxidike (Exacter of Justice) had a son Ktesios (Household) and daughters Homonoia and Arete, who were called Praxidikai (Exacters of Penalties) after their mother."
- Aeschylus, Seven Against Thebes - Greek Tragedy C5th B.C.
- Suidas - Byzantine Greek Lexicon C10th A.D.