Essence for the Engines

As the X-52's chief of engineering, I have to see to it that the nether-rocket's main engines are in tip-top shape.$B$BUnfortunately, I haven't built them yet.$B$B$C, I'm in dire straits here! I have almost all of the parts. All that I'm missing is the engine core.$B$BLuckily for us, I think we can make use of the essence from the local mana wraiths to jump-start the engines.$B$BThey can be found near most of the glowing trenches in the northern part of the island. Except for here in Area 52, of course.