Quick Update: I have now completed 1000 dungeon runs post 0.35 (~85% between 70-75, the rest level 100), opening every chest but wooden along the way (either through keys or minions), although i might have salvaged a few iron chests if I’m honest. For my efforts I have 1x Iron Nails. So assuming that Relics only appear in Gold+ chests (which means your chance of even having an eligible chest from a dungeon run are 31%), my “calculated” drop rate from eligible chests is about 0.3%, from all chests (i.e. Dungeon completion) is about 0.1%. Small chance indeed!