I assume you're talking about Arlana.
First, I would like to thank you for your patience and for engaging with the mechanics. What was your strategy when dealing with her? I would love to hear your opinion on her.
Next, as for enemy critical hits, I apologize for the imbalance. The game is currently agnostic as to which battler can land critical hits, and I didn't realize until it was too late that the game's inspiration never let monsters inflict critical hits and only allowed players to inflict them through normal attacks. I am working to correct this for the coming update.