Talk:Skeletron Prime/@comment-26573789-20150721190007/@comment-25211243-20160116205218

You should make another world (which has Corruption), defeat the Wall of Flesh on that world, then go into the Corruption and farm for Souls of Night. Or you can just kill loads of monsters to get a spawner and place lots of dirt and stone around your Crimson so that it naturally spreads (it will do that on hardmode)