Complex sentence: For the majority of the episode he has the other Inhumans battle the Agents of S.M.A.S.H. He is eventually exposed and defeated, though he reactivates the barrier that shields their city from the rest of the world, but it is destroyed by Black Bolt.
Split into simpler sentences: For the majority of the episode he has the other Inhumans battle the Agents of S.M.A.S.H. He is eventually exposed and defeated. Though Maximus reactivates the barrier that shields their city from the rest of the world only for it to be destroyed by Black Bolt.