Mafia 91. Experimental Redemption.

Plyukhin -> Plyushkin's syndrome -> Diogenes syndrome -> Diogenes -> died in 323 BC -> Philip III Arrhidaeus ruled from 323 BC -> the one harmed by the wife of Philip II - Olympias. In my opinion, it's an obvious case of toxaulica. Execute Arandor.

In my opinion, Plyukhin has a weak connection to Plyushkin's syndrome, and the latter, in turn, has a weak connection to Diogenes syndrome. The clue pointing to Plesa is more logical, but too simple.
Regarding chronology, I really don't like Val d'Emerol. She is too actively trying to whitewash herself with the block and joined the Arza slander too quickly.

Added 2 minutes later
Execute Val d'Emerol.