When we first meet Wallace, the blind replicant creator who has taken over production from Tyrell, he makes it clear that he has a massive god complex, and that he loves to go monologuing.

Is Wallace human or replicant?

In Blade Runner 2049, industrialist Niander Wallace (Jared Leto) is the leader of the corporation that now makes replicants. Wallace is blind, which is ironic, considering Tyrell, the last person to own the rights of replicant manufacturing, died without his eyes.

Why did Wallace kill replicant?

Wallace kills her because she cannot breed.

Wallace is trying to create replicants that can have children.