Loki was sure that he would tell the truth if he were tortured some more or threatened with death because Serge didn't want to die at all. Serge was willing to do anything to preserve his life, but Loki didn't take advantage of it.
Loki would only torture Serge for random reasons, which made Skarg anxious. After a while, Serge offered to tell the whole truth as long as Loki signed a contract stating that his life would be spared.
But Loki only smiled. He didn't sign the contract, and he didn't force Serge to tell the truth. He continued to torture Serge until he had his fill of fun.
After he was done, he used the Memory Read Metac to scan Serge's mind for everything he knew about Slav and their Skarg. But his search came up empty. Serge truly didn't know where Skarg had taken Slav or why Slav could awaken the Core Metacs of the Luck Pathway, Time Pathway, and Space Pathway.
