The Irredeemable Exception

SPOILER WARNING
4 vs. Satan:
*NONE
Alex in Princess Quest:
*NONE
The Stone of Power:
*RM: Artimus and Rawn no longer wish to use the titular stone. Cue to Balthar taking the stone and doing as much carnage as possible before his downfall.
The Three Kingdoms
*NONE
Dragondawn
*NONE
Harter Knall
*The S6-unit eventually turn good. Not so for King Greyland, General Dammur and the unnamed informant.
Hero Story
*NONE
Kill the Demons
*NONE
Satan Saga
*NONE
Story of Hero:
*Discussed with Eli Tataros. Jason outright calls him the sole irredeemable of the Tataros-cult while every other (including those who never reformed) could've been theoretically forgiven.
The Legend of Devils
*Satan and Darrol. Just about every other villain gets some sort of sympathy.
The Sidestory Duology:
*NONE
The Time Of Bloody Fear:
*Game 1: Maltros and Rosh are the only two villains to not get any sympathy. Even Reika, despite masterminding a murder, and Feeza, despite gruesomely killing someone, get some sympathy.