Switch your strategy, try other fighters.
I used Hazel as main, didn’t die once.
Not sure if there’s a stat requirement for it, but I just blocked the impale every time.
Viewing post in Corrupted Kingdoms (NSFW 18+) comments
Yeah, just defeated Ophelia with Hazel (as a support instead of a frontliner). Her support skill to passively buff physical is pretty great. I just kept defending and then buffing other stats like morale and defence whenever Ophelia was trying to counter. And then run roughshod over her once she was barely able to do chip damage.