There isn't a direct translation but you can use synonyms to describe the same thing. If you mean it in terms of a poem "tey" (tale) could work, if you mean it as the adjective "awesome" I would suggest "morokei" (glorious).

Another option would be "of legend" (legendary, "do zoor", "-sezoor"). That would be the Medieval equivalent. "Epic" actually comes from the Greek word epos (word, song), so "do lovaas" or "-selovaas" are other options. Another is "hun" (hero) -> "heroic" is "do hun", "hun (object)" or "-sehun"

For example: "That legendary sword" -> "Daar zahkrii do zoor" or "Daar zahkriisezoor"

"The epic tale" -> "Fin hun tey", "Fin tey do hun"< "Fin teysehun/teysehunne" (tale of hero/heroes), "Fin tey balaan do lot lovaas" (The tale worthy of great song)

"That