Aside from the Eraser, there isn't really any "creators" of the Multiverse. The Eraser's only job is to erase anything that breaks the sequence of events that is placed upon itself.
It’s erasure is defined, as long as the erasure doesn’t ruin the sequence of events, it will be played out. The Erasure can erase the past or the future, or both at the same time.
The Eraser has a large connection to the Multiverse, some calling it the "humanized" version of it (though this is not confirmed). The Eraser may have been the creator of me, though not even I know for certain.