The other other cube of fate reward. Currently, they're only useful for crafting the lvl 80 necklace, which is underpowered compared to regular gear.
Puzzle Cube under powered compared to Dragon Neck? mmm I don't think thats right, its about the same. There is a drop of 5% HP but you increase 5 attack and defence levels
That's the one made with Cogs of Fate. There's three levels of cube neck: lvl 60, lvl 80, lvl 140. Check the forges in CoF.