最悪の友と敵は死にほかならぬ。

the worst

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

friend; companion; comrade; pal

if; when; and; with; particle used for quoting (with speech, thoughts, etc.); quoting particle; promoted pawn; indicates question (sentence end)

opponent; rival; adversary; menace; danger; threat; enemy

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

death; decease; death penalty (by strangulation or decapitation)

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although