Nagato railed to Konan about the crooked and corrupted ways of the Shinobi World. He was also railing her about his plan to use the Bijuus powers to destroy the most powerful and prosperous countries, creating pain and suffering so more people can understand each other's pain, leading to world peace.
Rail:
intr.v. railed, rail·ing, rails
To express objections or criticisms in bitter, harsh, or abusive language.