Historical clue formulations

• Pettily punishes — 2020-11-01
• Treats vengefully — 2016-01-10
• Thwarts for petty reasons — 2013-07-19
• Gets back at angrily — 2006-10-25
• Is venomous to — 2005-06-19
• Treats vengefully — 2001-09-30
• Treats with 26-Down — 2001-05-11
• Gets back at — 1999-12-13
• Treats maliciously — 1997-07-10
• Treats with malice — 1994-09-26