I don't think Corrupt Rescuer is OP but I think she has one too many powers.
Reviving an ally with full health and granting Endure for all allies for two rounds is an excessive skill.
Her Titan Sheild every round means she can be very hard to take out first round if you go first. Do it first and I don't have a problem with teams with her in. Fail to do so or attacking other characters first and she brings them back to life is the problem. Gone from near victory to defeat because whom she revived and not being able to kill because of endure.
Take one of those skills away and i think she'll still be powerful and a danger but not have too many powers.