Zerg Evil God of the Heavens

First he became the Hive Mind, and then he brought his younger brothers to join the team of the Old Ones. The only problem was, "Little Tyranids, two new people have joined, and they said they know you." "WAAAAAGH!" Why did these two greenskins also come? This is a story about Tyranids and Orcs cooperating to cut down the world together.