Calamity happens if they so much as think about engaging.
Conquest wouldn't even work given WoU
1. Can't even kill itself.
2. Calamity happens without any act of will from WoU or Toru, they have zero idea how or what will happen either, just that it "will".
Makima literally can't even do anything to stop it and neither can they.
BFR? Multilocation yes multilocation, it's teleportation only because the profile predates that ability on wiki, I would know given I made the thing and is a law of the universe, BFR'ing one of its billion avatars won't do anything unless she can somehow BFR the law of Calamity across the world (She can't).
Control? And then what? The issue of calamity still happens and she just keeps dying. And that's assuming it'd even work on it, especially if she gets decapitated by a stray leaf for attempting it and quickly realizes whatever tf this thing is, might be a lil built diff.
Outlasting? Universal law. She's running through all of Japan before WoU dies, in fact it literally can't die as she's dying because I would wager a random civ getting murked falls under a Calamity.
Killing him? Type 8 Immortality.
And that's assuming she can, the calamity she endures is greater the more she pursues. So much as touching him or landing a hit is death, seeing his face directly is death, etc.
The longer she keeps it up, the worse it will be. And this is all automatic, passive, done regardless of if they want to, and is also all duraneg. She's gonna be dying constantly and they don't have to do anything unless she gives up and never interacts with him nor thinks about engaging him ever again.
That's also best case, it can even mess with other's abilities to an extent making them backfire or not work properly, like what if her shit just decides not to work or it backfires on her?
She literally can't win unless she has Pochita on speed dial and can somehow get him to eat all of WoU. Actual stomp, def not fair to her when only thing she can do is give up, or dies a slow death after WW3 starts so Japan gets wiped off the map.
Never forget WW2 happened because Lucy wanted to go back to Japan to pursue WoU.