Senior Aum Shinrikyo figure Tomomitsu Niimi filed an appeal Thursday with the Supreme Court, seeking to overturn the Tokyo High Court’s decision the previous day to uphold the death penalty for his role in several of the cult’s murders, including two sarin attacks, his lawyers said.

The lawyers claim hanging is too harsh a punishment for Niimi, 42, reckoning that as Aum founder Shoko Asahara’s most loyal disciple, he had no option but to follow the guru’s orders.

The Tokyo High Court on Wednesday upheld the district court-meted death penalty against Niimi, with the judge saying there were no mitigating circumstances.

He was found guilty of conspiring with Asahara and other cultists who carried out the March 20, 1995, sarin attack on the Tokyo subway system that killed 12 people left more than 5,000 injured.

He was also convicted for his roles in the June 27, 1994, sarin attack in a residential area in Matsumoto, Nagano Prefecture.