Illager/Villager conversion

Turning Illagers to Villagers would make a great feature in Minecraft. Potentially have a transformation similar to the zombie villager into a villager, having to trap the illager and give it an effect of some sort and give it something. I couldn't decide what to give it but it would have to be different. Emeralds and slowness? I would also think a villager that turned from an illager would have similar eyebrows to an illager, just less angry. Why worth converting instead of just killing them on the spot? A villager changed from an illager would most definitely have better trades or the ability to ring a bell anywhere in the village in case of a raid. Also I think it would be fitting if evokers can turn villagers that were illagers back into illagers.