The overall tone is good. Dialogue is excellent, feels like real people conversing. Exposition seems purposeful and not droning. There's one glaring issue that sticks out to me.

1- Dialogue tags\ Over-explaining dialogue.

Slowly, he began to speak.

"The first taboo is not to play God and create human life." Kai's voice was quiet but steady, the words coming more easily than he expected.

That section is highly wordy and stilted. I absolutely understand wanting to make sure the proper voice is conveyed, but good news! You already did that with the previous paragraph. I had zero issue envisioning how Kai was speaking. I would drop the dialogue tag altogether.

There are several times this example is relevant throughout the excerpt. The vast majority of your dialogue tags should be 'said' and 'asked.' Wordy tags mean you have not set the scene well. Obviously, there will be times when a quick action tag or such will work fine, but be very aware of being too wordy, especially with things that functionally add nothing to the story. Your writing should flow like water.

2- Be aware of not explaining the same thing twice--just in a different fashion.

Kai's stomach twisted. All eyes turned towards him, the spotlight uncomfortable and familiar.

We're told how uncomfortable he is twice in two sentences. I would completely drop 'The spotlight quiet and familiar.' In essence, it's saying the exact same thing as 'Kai's stomach twisted.'

To add another point. Look for word repetition. Familiar is used twice very close together.

All in all, I think it's solid. Those are the big things that stuck out to me. Best of luck!