Arika is a lead diplomat sent from Helena, a mysterious and militant matriarchal society in what was once Salt Lake City, which maintains a tenuous peace with Vega. Arika arrives in Vega as part of a negotiating party. A stranger in a strange land, she shares a clandestine relationship with David Whele. She is later revealed to in fact be Evelyn, the queen of Helena, in disguise, and is in a relationship with Uriel. When season 2 starts, she seems to be behind Claire Riesen with the issues of Vega. It is still unknown why Arika is using Claire and she isn't seen with Uriel right away. However, she is seen to be telling her true lover (a woman doctor from Helena, named Daria) that she only used Uriel to get what she desired: ruling Vega.
Gates however catches her and has Claire imprison her. While in prison, she attempts to poison Gates in order to have him betray Claire and release her, but he finds an antidote and mocks Arika for trying to blackmail her. Later, she is seen infected by the Amphora that was released by Gabriel onto Vega and hallucinates herself replacing Rose's place as an Eight-Ball and having Claire interrogate her as if she was a thing rather than a human being. She is shown to fear imprisonment, vulnerability, and complete isolation while under the Amphora's spell. She also contemplates all that she's done to people in her life and regrets hurting them. After Claire gives her the go-ahead, Arika flees with her allies to fly back to her home city, Helena, via helicopter. She shares a heartfelt goodbye with David Whele before leaving Vega for good.
Arika was a young child as she and her family witnessed her neighborhood being possessed by Lower Angels. Instead of fleeing, Kali, Arika's mother, and her aided the wounded civilians of the once-Los Angeles. Arika grew to care for the civilians of LA as she dealt with the casualties of war. However, both of Arika's parents were killed in the days of the war and Arika forced herself to maintain a fire and brimstone view of ruling the newly established Helena.
Evelyn is a scheming, unscrupulous woman who is willing to offer herself sexually to others and capitalize on any asset or opportunity to achieve her ends. She is shown to be a calculating leader. She is cunning in her approach with politics and knows how to get around the system. She lies and schemes to see her position increase and prosper, especially in a society full of war. However, after being infected by the darkness of the Amphora, Claire and Rose (an Eight-Ball she killed), interrogate her as if she was an Eight-Ball. This eventually leads to breaking Arika completely; Arika appears to now regret all the things she has done to people. She is emotionally distraught and unsure of what to do now other than to go back to Helena. She becomes more kind and helpful after her hallucinations during the Amphora epidemic that occurred in Vega.