In Terraria (Mobile), the guide is talking to me so my next step should be to destroy a Shadow Orb. Since I have the Crimson, i don't have the Shadow Orb, and according to the Wiki,
Pulsing Hearts in the Crimson act the same as Shadow Orbs in the Corruption.
Well, I did destroy like 9 hearts and killed 3 Brains of Cthulhu, but the guide is still idle in the same two messages. I did destroy the Skeletron, I have a big village and I am almost ready for the Wall of Flesh. I don't want the Guide's missions to be still stuck on the second task.