ἔσσεαι

From LSJ

τὸ πεπρωμένον γὰρ οὐ μόνον βροτοῖς ἄφευκτόν ἐστιν, ἀλλὰ καὶ τὸν οὐρανόν ἔχουσι → fate is unavoidable not only for mortals, but also for those who hold the heavens

Source

French (Bailly abrégé)

2ᵉ sg. épq. fut. de εἰμί.

Russian (Dvoretsky)

ἔσσεαι: эп. 2 л. sing. fut. 1 к εἰμί.