Evel can only be recruited by Creation by failing the "First Encounter" story mission. This includes being defeated in battle or not entering the portal at all and letting it time out. The following day an event can trigger, where Hebi urges the MC to take in Evel. If you accept, you get fucked in the ass and she joins your team.
Do note that the event is chance based. It's not a bug if it doesn't trigger immediately.
Like Creation and Hebi, Evel can use SpawnTentacle and SlimeBolt, and though Evel's powerful stats allow her to take any offensive role, be it brawling, casting or seducing, her Claws and Swing attack along with ShadowStep and Agile give her greater capacity for frontline damage than the other two.
- While Evel is a solid addition to Creation's party, it is debatable if its worth picking her over the other first mission rewards, particularly the Empowered trait. There are definitely pros and cons depending on what you chose at the beginning, so try her out.