MC/ SI defeats Cauldron/ Contessa and the Simurgh

So the issues with any SI or pretty much any fic where meta knowledge exists is that Contessa and/ the Simurgh would pretty much know something is up right away unless being a blind spot to them is included and even then, it is just putting things off until the SI changes the plot enough to get noticed by their effect on the world.

I'm curious how authors have solved this issue in their fics and the only real way I can see it working is if they are somehow able to defeat both Contessa (and the rest of Cauldron when they find out) and the Simurgh (and maybe the rest of the Endbringers/ Scion if things escalate). Oddly enough Cauldron's reputation in fanon makes me feel like the Simurgh is more likely to be able to be negotiated with successfully than Contessa or any of the main people of Cauldron except maybe Legend.

So please give me a bunch of fics where the MC/ SI is able to effectively neutralize both the threat of Contessa and the Simurgh.