Wendy vs Crab King
There's probably a better way to do it, but this is my current strategy.
Crab King really highlights the shortcomings of Abigial's AI as you have to quite a bit of effort to get her to attack Crab King. Also, you would think that Abigail would help cancel Crab King's healing, however it's actually harder with her if you decide to socket 2 Orange Gems.