If they are biological rather than magical, you want to keep in mind that they are relatively fragile, though with a lot of muscle behind them. You don't want to risk them if at all possible, so your direct combat usage of them should be limited to pummeling the enemy from the sides while you have their weapon locked in place with your own, or have disarmed them. Strikes from the wings of certain birds IRL can shatter bones, so there is a lot of force potential there, though you would need to be aware of the possibility of striking hard enough to break the wings too.
Indirect application is where wings shine. Use a long spear and dive feet-first at the enemy, bracing the spear with your feet and using the enemy to break your fall. It is very hard to defend against a piercing attack from above, especially if you don't have a shield. Likewise, you can jerk open wings backward to provide a boost in forward movement for a very rapid lunge, also adding force for a piercing attack. The opposite is also an option, allowing a backwards dodge at vastly higher speeds than most would expect, allowing rapid disengagement, potentially even allowing you to pretend to meet a strong blow only to dodge back at the last instant, causing an opponent to overbalance and make themselves highly vulnerable to a followup strike. Said followup could be assisted with using the wings to lunge forward again, as well.
Additionally, keep in mind that using wings costs a great deal of energy compared to legs, so overuse would rapidly exhaust someone. That said, they are also great for rapid transit across the battlefield, thus being a huge boon to healers/medics by allowing them to reach wounded much more rapidly, and bypassing ground-based threats.
