If one country controls all of earth and has a single ruler (with at least as many powers as the 2024 U.S. president), that counts as earth being a single ruler state.
Resolves as 'Human-AI hybrid' if it has both human brain and other hardware AI, and neither part can easily turn off the other one (a human with implants that can be deactivated to not impact decisions would count as human).
'AI' has to be your standard human-built AI. An AI coming from space and subduing earth would resolve as 'Aliens'.
'Aliens' means our overlord originates from outside of earth (and they have not arrived before 2024).
Dolphin-AI hybrids or similar resolves as 'Other'.
(with at least as many powers as the 2024 U.S. president)
I believe this definition is net negative for the question. It could well be that this happens and the ruler does not have some of the powers the POTUS has today - for example, if Trump and guys similar/worse than him abuse the power of pardon enough, that power might not be available to this hypothetical President of the World. There are powers that don't even make sense - who would this world ruler sign treaties with?
The question is well-defined enough as it is now, without that phrase. I suggest you axe it.