When you use a werewolf lure (or any lure really), it increases the percentage chance of capturing the enemies linked to that lure.
If the 'turns' number is over 100, you have 100% chance of capturing the creature.
So either beat it down to low HP (or tease it up to nearly max lust), then use four or five lures to get it to 100%, then defeat the enemy (with either HP damage or by Lusting them to max) and you'll capture them.
Note for werewolves, you'll also need a reinforced prison back home to contain them.