I think this was a great addition, and making it a challenge to get the new SR Toon 6S.
But these are hard given the amount of special zombies, esp after level 400. The time it takes to complete it is NOT worth the REWARD. THESE SHOULD OF BEEN SCLASS in a month or so 90 % of all 6s will be out of the META.
Immune to a headshot, that goes against zombies. I like the IDEA but way to late, and way to much time and frustration, for another shield that will be like FA TARA