This is so cool! The third ability reminds me of the Knight's Challenge, and it's a good call for a protector. One of the problems I had with 'tank'-type characters in 3.5 is that most of them have no real way to compel or encourage opponents to attack them rather than weaker characters. Binding Marack is definitely a more palatable alternative than the somewhat mediocre Knight class, and the bastion ability improves it even more by allowing you to suck away damage from other opponents.