There is two ways to capture an invader. 1. Fight them till they are weak of mentality or high on lust, then use a collar in the item menu. ( the chance depends on their mentality and lust)
2. Some has ability to capture in battle, so if you have a character you wanna use to capture an invader, then make sure it has the ability of capture.
Fun fact: You can still capture them when they on no health, as long you dont end your turn. Otherwise they just die at the end of your turn.
1. Using a Collar (buyable, or can be crafted for some cloth) on an invader when they're lower on health. (You can hold on to two at a time, increases by two more for every Prisoner Cell / Binding Cell you have.) Some also have an ability that lets them capture invaders.
2. If you have a Graveyard and an Altar, you can kill them, retrieve the body, and resurrect it as a zombie. (If you don't mind them being a zombie, that is.)
