"I am Kapahamatu, I am unity."
What does this even mean? Is he a Force in the universe, is he some sort of hyperspace node? No, he is a typical Alien Blowhard trying to take over space
"You are weak, hopeless without us!"
We at Trantor have dealt with greater crises, such as evacuating Terra from its destruction, and defending space against invaders from another Universe.
"You do not understand our role in the formation of your galaxy. We were there from the beginning and we will be there until the end!"
We Trantor aren't even from this Galaxy, we moved here several thousand years ago, so this is little more than garbage from some blowhard insane man.
"Every technological innovation, every breakthrough in science, every cure for every disease, all thanks to us!"
Not really, Trantor inventions come from known trading partners, investment, and our own research squads, not some sort of Alien God, but thanks for trying!
"We helped your people survive, grow, evolve! We are your protectors, your guardian angels!"
The Angels were horrible monsters we had to defeat on World X-1, so that isn't even a good term! What next, they will become Devils?
"Yet, you treat us like your enemies, like we did nothing to help you, only to spite."
You said yourselves join us or die, and you expect people to roll over and die? Who the hell do you think we are?
"You do not accept us, you do not want unity, thus you must be eliminated."
So now you say Genocide? And you expect people to follow you? You are terrible and fail to understand how things worked around these parts of Space. You do not just come in and say "Join us or die," that leads to war and conflict. We ask you to stop this conflict, please.. War is not a good answer!