Paladin, the title says, and the poem treats its heroes almost like objects. The subtitle "Ancient Artifact" invites us to picture them as old weapons or relics, made with a purpose and used until they break. Their "steel teeth and iron bones" sound strong, but the language of being "made" hints that they never had a choice.
The poem is built on a turn. The first stanza praises them as heroes who sacrifice and love humanity as a whole. The second takes the same qualities and shows the cost: they dull, bend, warp, and die "in the name of fate." Being a hero and being a martyr turn out to be the same thing.
The speaker seems quietly sorrowful rather than angry. There is admiration here, but also grief at how much is demanded. The short final lines, "they will; until there is nothing left," give the mood a steady, resigned weight, like a vow that can't be broken.