σωστέος
From LSJ
Τὸ νικᾶν αὐτὸν αὑτὸν πασῶν νικῶν πρώτη τε καὶ ἀρίστη. Τὸ δὲ ἡττᾶσθαι αὐτὸν ὑφ' ἑαυτοῦ πάντων αἴσχιστόν τε ἅμα καὶ κάκιστον. → Τo conquer yourself is the first and best victory of all, while to be conquered by yourself is of all the most shameful as well as evil
English (LSJ)
α, ον,
A to be saved, Aristid.Or.24(44).37. II σωστέον one must save, E.HF1385; you must be saved, Ar.Lys.501.-- The form σωτέος is cited by Hsch., Phot., Suid.