Keeping the Sword Saint and treating him with respect was a gamble on hope. After all, he was once a terrifying existence who had reached the Second Rank, a man who could create miracles. Surely, he would be familiar with them?
Even if it didn't work out, supporting him wouldn't be a major issue.
Besides, to be honest, the expense of keeping a Sword Saint was far, far less than his own upkeep.
