there are 4 rewards for handing in the 4 different essences from the 4 EP bosses.
-cord of invigoration(belt with effect cloroplast worn)
-Jade hoop of speed(haste earring)
-mace of the anchient(22/23 1hb with effect anchient call)
-ring of farsight(ring with stringed instruments, composure worn and focus of distance)
all items have between 150 and 170 to both hp and mana and 20+ to some stats.
you can also keep turning it in to get the item you want, just like the white dragonscale boot/helm/sword quest in SS.