The 4th Mugo is the one who gave the MC the key to not be eaten, it wasn't glasses Mugo. Glasses Mugo is in favor of eating sacrifices, Mean Mugo just goes along with it and 4th Mugo stopped them from eating this one by telling MC to bring Glasses Mugo something sweet. That's why Glasses Mugo saved him, not because he originally wanted to.
The 4th Mugo is the one who gave the MC the key to not be eaten, it wasn't glasses Mugo. Glasses Mugo is in favor of eating sacrifices, Mean Mugo just goes along with it and 4th Mugo stopped them from eating this one by telling MC to bring Glasses Mugo something sweet. That's why Glasses Mugo saved him, not because he originally wanted to.
The MC's protector is the 4th Mugo.