A simple system of raw, refined metals and metal alloys could be put on DST.
By introducing iron and carbon, steel could be produced, with which weapons and armor decidedly superior to wood could be made.
Carbon could be obtained by refining coal or ash, and then casting it with iron through a foundry (similar to that of Hamlet.)
Exotic and fantastic materials could be added, such as adamantium or orichalcum; obtained through ancient meteorites or mines populated by golems and ancestral guardians. I'd love if a new endgame material were literally "degenerate matter", similar to that of neutron stars, ultra-compact matter capable of forging semi-indestructible armor; perhaps the result of an ancient "particle collider" which imploded on itself when in remote times THEY came and brought the ancients to disgrace. (Assuming THEY really did anything beyond watching.)
