: You can complete multiple challenges in a single run by saving right before a kill, performing the kill in different ways (e.g., poison, accident, sniper), and reloading to get credit for all of them at once.

If you want to without consequences, buy the Unlock All Shortcut DLC from your platform’s store. It costs less than a fast food meal and supports the developers. If you are on PC and willing to risk a reset, a 100% save file from a reputable modding site works. Avoid memory injectors at all costs.