Just work around it like everything else, shock is great for this. It may be a little op now but when we start getting toons that apply aoe healing block or more toons with shock or something like that then no one will use her anymore. Yes I know she dispels negative effects but you just need to burn town the target when shock or healing immunity is up. She is ftp so no one should really be too upset imo.
Disclaime: I don't use barris zeta, I do not have barris past 5*. I just don't think the team is unbeatable- it is tough though without a doubt