Use the tools she has. BKO 6p is i12 and goes under i9 jabs. BKO 2/8p+k will sidestep vs most i11 mids and will also beat out the i9 jab. Not to mention BKO 22p will shut most of it down. Helena's fine.
Shes actually not fine overall, Her okizeme and damage output made her an actual good character in doa5lr but now her damage is average/her okizeme is trash because this games entire meta just basically rewards you for having an otg grab. Her neutral was always subpar so what the fuck does she have other then evasiveness which the system tools work against her.
oki is weaker for everyone now, not just helena, and helena's dmg has always been low, even as far back in 2, if anything her doa6 counterpart is more faithful to old helena who was always a character who had alot of ways to open you up, but once she knocked u down that was the end of her pressure, doa5 helena was an outlier thanks to how force techs and oki worked in that game, now u gotta use your brain a bit more
Helena can still force really good oki imo where others can't unless you're a grappler. As for her neutral, she has bko. Characters have to play by her rules and play around her crushes because she can easily disrespect you in the neutral.