ἔργοισι χρηστός, οὐ λόγοις ἔφυν μόνον → a friend in deeds, and not in words alone
subs.
Use Ar. and V. Ἐρινύς, ἡ, P. and V. ἀλάστωρ, ὁ (cf. Aesch., Pers. 354).