Started: At Deogath Shrine, Rumari Lake
Items Needed: None
Items recommended: Armor, golden apples, bread, diamond weapons, ect.
Difficulty: Really Hard
Reward(s): Diamond weapons, golden sword, slime ball, diamonds, bread, golden apples, random blocks, torches, diamond armor, and some other misc. items.
Head to the Deogath shrine, north of Imperial Lands , really near Snowville , should be really easy to see from a high place at the city since the Oblivion Gate is huge. At the shrine you will find a follower that will explain you the situation, telling you that you must close the gate before the ghasts come again at night along with the zombie pigmen and other creatures.
Get inside the gate, you will enter into the nether realm, descend and find your respective nether tower (each oblivion gate has his own nether tower). This nether tower is one of the hardest ones and it is located in the middle of the lava doom, a huge lake a nether, again, it should be really easy to see since its the highest tower at the nether.
Battle through every floor, the higher you get, better rewards and harder monsters, if its a dark floor, place torches, otherwise golems or creepers will spawn. At the top, you will find a boss, in this towers, bosses are ghasts, DON'T WASTE TIME KILLING HIM, take the sigil stone (slime ball) and get out of the nether, well, not here is the problem, finding the portal, since the tower is really far from it, you have to look around, however, there are some signs that will lead you to it, also, there are cobblestone tower with ladders, that means that they lead you to the portal. Remember, you must ascend to it.
NOTE: Watchout, if you are really slow, then the boss, the tower Succubus will kill you!