Complex sentence: To achieve this, he creates numerous beings called "Nightmaren", including two "Level One" Nightmaren, acrobatic jester-like, flight-capable beings called Nights and Reala.
Split into simpler sentences: To achieve this, he creates numerous beings called "Nightmaren". Level one Nightmaren are two acrobatic jester-like, flight-capable beings called Nights and Reala.