mitigator (?.)

• alleviative
• alleviator
• anodyne
• assuager
• balm
• calmative
• cushion
• dolorifuge
• lenitive
• moderator
• modulator
• mollifier
• pacificator
• pacifier
• palliative
• peacemaker
• restraining hand
• salve
• sedative
• shock absorber
• soother
• soothing syrup
• stabilizer
• temperer
• tranquilizer
• wiser head