Bestowing mercy on one usually involves stealing justice from another, almost always without their consent.
It's a thing to keep in mind when people invent a modern Sweet Jesus who is ever merciful, ignoring those who have been deprived of justice. Mercy that is not built on a foundation of justice is mere capitulation to inequity. It is cowardice, not courage. Mercy can of course exist and is the highest good. But the bar is high that prevents it from being a sham, a disguised cruelty that rewards one's friends at the expense of the deserving.