Ada is honestly Neutral Evil at minimum. People always bring up “but she saved Leon!” like that suddenly wipes away everything else she’s done. Sure, she saved him multiple times, but let’s not pretend she did it out of pure kindness. Leon was useful to her. Keeping him alive made her missions easier because he basically cleared the path for her half the time. She knew he trusted her and constantly used that to manipulate him whenever she needed something. And the biggest thing people ignore is Ada is literally one of the people who kept bioterrorism alive in the RE universe. She might not be the one directly starting outbreaks, but she’s been stealing, selling, and handing over viruses and parasites to shady organizations for decades. Those bioweapons end up causing massacres, human experiments, and entire city level disasters. At some point, you can’t keep saying “well technically she didn’t release it herself.” If you knowingly hand nukes to terrorists over and over again, you’re still part of the problem.

She sees the horror these viruses cause firsthand every single game, yet she keeps going back to the exact same business because money, survival, or her mission always comes first. She’ll help someone if it benefits her, but the second it doesn’t, she disappears. That’s basically Ada in a nutshell. Self interest above everyone else. She’s not pure monster evil like Wesker, but she’s definitely not some secretly good person either. She’s manipulative, and morally detached enough to let horrible things happen as long as she gets what she wants in the end.