Don’t kill people with kindness, because not everyone deserves your kindness. Kill people with silence, because not everyone deserves your attention.
There will be times in your life when you need to or have to defeat someone. A competitor in a competition or someone who wants to harm you; Either you or they, must fail.
You can compete fairly, or be kind to your enemies. But don’t be kind in all cases, because not everyone deserves your kindness.
When your opponent cheats to win you, or when they use tricks to defeat you, they’ve broken the fairness required of the competition. They, themselves, have lost the rights to be treated kindly.
You do not need to care about them. They deserve it. Just ignore them and focus on what you have to do, focus to get what you want to have.