To fully understand War of Underworld , you should follow this sequence:
Episodes 1–24. Ends with the battle against Administrator. Sword Art Online: Alicization - War of Underworld
Episodes 25–47 (often split into Part 1 and Part 2). Plot Arcs & Synopsis To fully understand War of Underworld , you
The "War of Underworld" sub-arc is divided into two main parts: To fully understand War of Underworld