Anyway, there's no need for specific execution, just need to move your lips.
When Salovis woke up and was about to take a lava bath, Leon casually told her to head to the Star Realm when she had time, to get in touch with those Red Dragons in Tunaras who served the Githyanki. Ask those Red Dragons to keep an eye on Vilakis and report any anomalies immediately; there would be a generous reward for useful intelligence.
As for dealing with Mephisto, Leon didn't plan to push it. The reason was simple: that Chief Mage of the Nine Prisons seated in the eighth layer, Cania, did not welcome visitors, so it was really difficult for him to intervene.