Final answer:
Counter-curses are used primarily to reverse hexes and jinxes rather than removing dark marks, enhancing magical abilities, or prevent future curses. They are a form of magic aimed at negating or undoing negative spells, often found in both fictional works and historical esoteric practices.
Step-by-step explanation:
Counter-curses in fictional and folkloric contexts can serve a variety of purposes beyond just healing victims. The correct answer to what else counter-curses can do is Option 1: Reverse hexes and jinxes. These forms of magic are often designed to negate or undo the effects of negative spells. While there are many fantastical practices in historical and mythological traditions, counter-curses in these contexts do not typically remove dark marks, enhance magical abilities, or prevent future curses outright, but they could lessen the impact or protect individuals temporarily.
Historically, as mentioned in the background information, practices like writing curse tablets intended to engage supernatural forces to benefit personal desires in matters of love, justice, and competition. Placing these tablets in spiritually significant locations, such as graves or water sources, was common in hopes that the invocation would be more potent. Nonetheless, counter-curses would mainly be focused on combating such spells rather than enhancing one's magical prowess or providing long-term protection.