a person who thinks too much grace, mercy or anything like that is beneficial. This type of person may continue to be one no matter the consequences. It doesn't matter what wrongs someone else did the overmercist will forgive them endlessly.
"Are you an overmercist?! He failed you 10 times!"
"Dude, everyone hates him for his bad doings but you seem to forgive him anyway? You're an overmercist"
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)