Nemesis, as in the original Infinity Being ... imo, stalemates THOTI.
God vs God ... there can be no winner.
THOTI may be TOAA's power, but it's their power within the omniverse,
basically as powerful as one can be within that fictional reality known as the omniverse.
We can't confuse ourselves with what TOAA is in actuality (outside of the omniverse)
which is a whole other level that can't be categorized
since it creates supreme powers (like THOTI & the IB) with the stroke of a pencil.
The Infinity Being was also all there was, and everything else was it,
the sole God of all things,
so it too was as powerful as one could be within all reality.