IIRC, it's not fully established what mechanism of her revival is, but it's suspected to be time reversal or something like that. I might be way off, it's been a while since I've read this, so... just keep that presumption in mind when reading my theorizing:
I feel like that killing platform either won't work on her (it'll kill her and she'll come back) or we'll find out that the way it works is by extracting those powers from people, killing them in the process, stores that power in some form, and once it stores enough, it'll awaken as some kind of doomsday device. If the latter is the case, I think one of three scenarios will happen:
1) we find out about it (at least part of that, the extract and storage portion) beforehand, and so she decides not to go through with it, but someone else uses it and it wakes up (or the main plot of the next arc is basically "how do we destroy this thing before it wakes up").
2) we don't find out about it until she's in there, but it doesn't fully work because, by the time it's extracted her power from her, she's died, her power activates, and she comes back to life via turning back her own time to before her power is extracted, rinse and repeat until it wakes up from being infinitely filled.
3) we don't find out about it until she's in there, but it doesn't fully work because it extracts part of her power, the rest activates, and the part that was extracted was basically a limiter and now she's even more OP because she gains the ability to do some or all of the following: control it at will while retaining memories, turn back time for not just herself but things around her, actually go back in time (and further than she currently turns back her own time) while retaining memories of her deaths so she can change the future, fast-forward the time of other entities, or something else I'm not sure of.