How did Palpatine react to master Yoda’s death? Mere moments before his own defeat, in between the scenes shown in Return of the Jedi, Palpatine and Luke have a deep conversation where he eventually probes Luke’s mind to discover who trained him. Already knowing that Obi-Wan trained the young farm boy for his first steps, Palpatine began to mock Kenobi’s death relentlessly, brewing a deep anger in LUke, exactly as Palpatine had hoped.
Palpatine then wondered who had continued the boy’s training after Kenobi’s death, but filled with anger Luke did not respond. As a result, Palpatine probed his mind and discovered that it was his old rival Grandmaster Yoda, who had survived the Jedi purge. Upon probing even further, Sidious discovered that Yoda was dead and began to mock the small green master’s death as well as the way he spoke.
Moments later, he defeated himself at the hands of Darth Vader.