The Advengers Have Taken Over Minecraft! You need 8 repeaters, 4 comparators, (throw all of the comparators and repeaters on the ground beside each other to get 4 circuits) 1 sea lantern, 13 iron blocks, 6 redstone blocks. Put the 4 curcuits on the ground and add 2 redstone blocks and 9 iron blocks to get your Ultron Core! Now place the sea lantern somewhere. Iron blocks will be in the corners of the sea lantern (four corners) And the redstone beside the sea lantern.