Something about Sunny Aggregator felt off-kilter to the cryptocurrency user known as Saint Eclectic. Sunny was the newest decentralized finance (DeFi) app to hit Solana during that blockchain’s scorching bull run last summer, when its native token jumped fivefold. Sunny was barely two weeks old by early September, but billions of dollars in crypto were flooding this yield farm. Still, Saint and others had questions: Who was behind Sunny? Why was its developer, one “Surya Khosla,” pseudonymous...