I would say B. You refresh cards at the start of your turn so when you refresh Lie In Wait you make the attack as instructed and continue with your turn. Grey Ker could then take his first action, and suspend his turn to use his second action later in the round.
Wow that's extremely strong. So with Grey Ker you can get 4-5 attacks in on the monsters before they even activate. I don't know if that's balanced, but I guess I will see.
It sounds like an effective tactic but I don't know if it is overpowered. You aren't gaining extra actions just manipulating when you get to use them. The problem with Lie in Wait is that you need a valid target at the start of your turn for it to work.