The riskiest and hardest way with the most potential for success is the torrent of shit. Character has a problem, and something outside their control makes it worse. They try to fix it, and results make this consistently worse. They sometimes get swept along out of control, sometimes miss chances to fix things, and sometimes fuck up under their own initiative, but the key element is that things get worse. They get better, then worse, then worse, then a whole lot better, then worse, then better, then fucking shit, or however you do it. The common thread is that no matter how shit things get this person keeps fucking going, even though they sit, they scream, they cry, they give up, but they always get back up. You can't help but feel for the underdog who just keeps trying; it's practically fucking encoded into us by societal conditioning. Then, the very last time, as the players try to help time and time again (and sometimes they have to fuck up trying to help the character; if they're a decent bit invested you can improve that investment by them doing something to make her hate them for a time so they have to win back her trust) until it just goes too far and she can't do it any more. There, if the players are remotely human, they will be so invested they want, almost NEED, to help, and if you let them feel they could, it will be the peak of their investment in this character. This is, incidentally, the perfect time for your sacrificial rite. You could have her torrent of shit being trying to escape the sacrifice, until finally it's all too much and she gives up, because she'd rather die than live like this any more. This is when your players will be charging in to save her.