None of the theories suggested thus far explain the last part of the quote:
but then she died at the hands of a troll, and yet you lived.
The way I see it, Lucius could have been thinking one of two things (originally, before Hermione’s death) to say that:
Killing Hermione would also kill Harrymort (e.g. Hermione is some quasi-Horcrux Lucius may have heard of).
Hermione would certainly survive anything that Harrymort survives (e.g. Hermione also has all the magic skill of Voldemort).
In the Bellatrix theory I’d interpret that as meaning that Lucius seriously doubts that Harry would survive something that manages to off Bellatrix. But I acknowledge that the phrase sounds like it means something more than that.
None of the theories suggested thus far explain the last part of the quote:
The way I see it, Lucius could have been thinking one of two things (originally, before Hermione’s death) to say that:
Killing Hermione would also kill Harrymort (e.g. Hermione is some quasi-Horcrux Lucius may have heard of).
Hermione would certainly survive anything that Harrymort survives (e.g. Hermione also has all the magic skill of Voldemort).
In the Bellatrix theory I’d interpret that as meaning that Lucius seriously doubts that Harry would survive something that manages to off Bellatrix. But I acknowledge that the phrase sounds like it means something more than that.