Kylier appears; now you have to kill Eudy. Taking out Eudy will remove the witches, so you don't actually have to fight them if you just ignore them through this part. Anyways, from Kylier's position, you can union (through linking) up to four units against Eudy. You'll also want to get your units close to that first Knight, because once 16-4 rolls around, they will abuse that bottleneck, making it difficult for you to move and create effective unions.