Hi again.
Field Spikes is a location that says: "Challenges: kneel Field Spikes to choose an attacking character with STR 2 or lower. Its controller chooses either to remove that character from the challenge, or to kill that character after the challenge resolves".
If I have a "cannot be killed" char with STR 2 (for example Small Paul) and I attack with him a player who controls and activates Field Spikes, what happens? Am I forced to remove Small Paul from the challenge? Or can I choose to attack anyway, and Small Paul won't be killed at the end of the challenge?
Thank you!