25: Attune Obelisk or Stone Circle. This is powered by lay lines and bound elementals.
Success: An obelisk can radiate a breathable atmosphere in a one mile radius, healing energy of 3D8 in a one mile radius, harming energy in a one mile radius, it can be linked to other teleportation obelisks(You must say the name of both obelisks to teleport there), or a stone circle can awaken any creature standing in the center during the spring equinox.
Failure: The obelisk has an opposite effect. Note that a poisonous atmosphere will attract fiends and aberrations. Healing and harming energies are opposite each other, so disrupting an undead ritual may be viewed as hijacking their ritual. The opposite of awakening is turning a creature into a total beast. And a reversed obelisk of teleportation will send a person in a random direction and send them 1:high, 2:low, 3:into a solid object(They take damage and appear next to a large rock), or 4:Into the Cleaves or astral plane if you are not using The Cleaves.
Modifiers: Knowledge nature and arcana. Summoned elementals add their hit dice to the chance of success. Livestock or people who get killed by accident or on purpose count toward the success of the ritual. Difficulty is a flat 30.
Cost: 3000GP which includes the cost of stone carvers, diggers, and stone porters. Getting all the townsfolk drunk and having the mob carry the stone or stones to the location counts.