Take the Elder out, he is hard hitting but his spawn altar area is a mass of indestructable pillars, take a decent bow with a large supply of fire arrows and pepper him to death while using the 4 pillars as a shield.
I take him on with bronze stuff, even move in to melee him, if he hits he hurts but you will get the pattern quick.

Then you can move on to the next stage, the iron age... I wont spoil stuff but its a pretty intense area, so make sure you have a portal near, spare poison res potions, and spare food for the death run.